RELATIVE EFFECTS OF SELECTED COMMUNICATIONAL 
STRATEGIES IN SOME BIOLOGY TEXTBOOKS ON HIGH 
SCHOOL STUDENTS;i LEARNING IN BIOLOGY
BY
ADESANYA IYIOLA ADELEKAN 
BteSCo Hons, (Ife)
MbA* (Ife)
.. g
*
■
A Thesis in the Department of 
TEACHER EDUCATION
Submitted to the Faculty of Education in partial 
fulfilment of the requirement for the degree of 
DOCTOR OF PHILOSOPHY 
of the
UNIVERSITY OF IBADAN
July, 1986
UNIVERSITY OF IBADAN LIBRARY 
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ABSTRACT
Textbooks have consistently been accepted as an important 
companion of science teachers and students,, With apparent 
inadequacies of laboratory equipment and facilities, coupled 
with the unwillingness of Science teachers to explore their 
environment sufficiently, most science teachers had struck 
faithfully to teIxtbooks as an easily accessible instructional
aid in shaping their knowledge in scienter Today, textbooks 
have been seen as a critical component of cburses than 
contact with actual living material* In addition to their 
roles as an instructional aid, textbooks have for sometime 
remained as a source of ihformation. Ih many develojpihg 
Countries, particularly in Africa and Asia, science has been 
largely held as a foreign knowledge whose understanding can 
best be appreciated and understood only by reading textbooks* 
This great dependence on books places a premium on the 
value, quality and significance of textbooks in impacting 
scientific knowledge and understanding. The pertinent and 
crucial question is, "To what extent should textbooks serve 
as facilitators of scientific knowledge and learning in terms 
of effective incorporation of desirable communicational
UNIVERSITY OF IBADAN LIBRARY 
iii
strategies?" This study had attempted an answer to this 
complex and multi-faceted issue*
In seeking an answer, ah attempt was made in identifying 
desirable communicational strategies expected in a biology 
textbook* Further efforts were also made to find out if 
four commonly used biology tektbooks in Nigeria are ihdeed 
within the comprehension level of students* Having identi­
fied the various communicational strategies in the four 
textbooks, the relative effects of selected strategies on 
secondary school Students’ learning was consequently l i
focussed upon* Porram four secondary school students (N = 154) 
drawn from three (two for experimental, and one for control 
groups) selected schools in Oyo State, Nigeria were involved 
in the study*
In addition, 50 people (which included teachers, 
students, education officials, publishers and authors) were 
involved in a survey r relating to desirable communicational 
strategies in a biology textbook* For the experimental 
setting, cognitive achievement in biology, the level of 
development of scientific attitudes and the level of acquisi­
tion of practical skills were the dependent variables of 
the study* The independent variables included the textual
UNIVERSITY OF IBADAN LIBRARY 
iv
conmunicational strategies, age and sex of the subjects* The 
Solomon—3 design was used for the data gathering* All the 
subjects were pretested, treated for six weeks and post- 
rested on all dependent measures*
The result of the study revealed the following:
1. There were significant differences in the number of 
factual, leading, probing and terminal questions in the 
four biology textbooks examined*
2* There were significant differences in the number of 
technical terms defined at; first occurrence, immediately 
after occurrence, later in the text and those not defined in 
the four biology textbooks examined*
3, Thebe were significaht differences in the rtutnber of 
local and non-local specimens, labelled/ unlabelled diagrams, 
labelled and unlabelled pictutes contained in the four 
biology textbooks examined*
4* There were significant differences in the number of 
evolutionary, ecological, economic importance, inquiry, 
historical and knowledge themes in the four biology textbooks* 
5. There was no significant differSnce in the number of 
traditional world-view themes represented in the four biology
textbooks*
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There were significant differences in the number of 
sirrcle, specific, general and challenging practical exercises 
re* rained in the textbooks examined.
There were significant differences in the views of 
= _r_hors, teachers, publishers, ministry officials and 
=r_cents in their preferences for questioning styles, speci- 
-ers, pictures/diagrams, practical exercises, major themes 
i-.c physical characteristics of biology textbooks. 
z • There were significant differences in the cognitive, 
affective and psychomotor performances of the experimental 
arc control group subjects with respect to questioning styles, 
technical terms, specimens, pictures/diagrams, major themes 
ar.d practical exerbiises.
On the basis Of the finding^, the ffallowing betotamenda-*
tions were made;
1* To promote cognitive effective and psychomotor perfor­
mances in biology, teachers should identify the merits of 
communicational strategies in biology textbooks, and make 
these textbooks available for teachers' and pupils' use*
They should also use in planned sequence, identified 
strategies in their teaching.
UNIVERSITY OF IBADAN LIBRARY 
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2. Authors and publishers should make use of a variety of 
conmunicational strategies in the preparation of biology 
textbooks., They should be conscious of the comprehensibility 
of the learning material they are presenting,. A constant 
review of published textbooks should be made along identified 
meritso
3. Ministry officials should involve practioners in the 
education sector in the selection of textbooks for students* 
use.
4. School libraries could be supplemented by the location 
of community/district libraries for a number of schools that 
do not have libraries.
5. A regular forlim (Seminars, workshops) should be 
organised for officials, publishers, authors, teachers and 
students where exchange of ideas on the merits of identified 
communicational strategies in textbooks can be discussed.
UNIVERSITY OF IBADAN LIBRARY 
vii
DEDICATION
Two individuals have consistently given me joy and 
inspiration - my son, Adefemi Adesanya Adelekan and my 
father Samson Adegbenro Adelekan, To *Femi who on many 
occassions stayed behind while I am working till late in 
the night - calling Daddy, and my father for his implicit 
confidence in education as a vehicle of social mobility,
I lovingly dedicate this work.
i
UNIVERSITY OF IBADAN LIBRARY 
viii
ACKNOWLEDGEMENTS
I give thanks and gratitude to Jesus Christ my Saviour 
and Lord for taking me this far - May his name be praised 
(Amen)* It has pleased God to allow the dawn of a fulfilled 
ambition* As I Set out to contribute and extend a little 
further the frontiers of knowledge, Jesus Christ had 
consistently being my guide, guidian and teacher at those 
trying periods when some problems looked rather unsurmountable*
I here recognise and acknowledge the contributions of 
Dr* M 0B0 Ogunniyi - my supervisor to this academic achieve­
ment* His dynamism and training brought to a clear focus my 
initial confused ideas and intensions* He had patiently 
taken me through the turbulent waves of the academic waters 
with its frustrations, depressions arid joy. I shall remain 
eternally grateful for not only his supervision, but particu­
larly for the brotherly and personal interest when I occassion- 
ally get discouraged and tired* Dr* Meschach Bolaji Ogunniyi 
within 3 months of supervision, patiently and carefully 
worked out an admirably strategy that had made an original 
confused plan achievable* He had within this short period 
endeared himself to me as a teacher whose concern for my
UNIVERSITY OF IBADAN
LIBRARY 
ix
academic achievements. knew no boiinds. He has done it on 
more than one occassion, and to many of his students he will 
remain a mentor. Apart from assisting in developing the 
instruments used in this study, he had readily made available 
an avalanche of literature used in the study. My family and 
I shall rdmain grateful to this versatile scholar.
I would also want to place on record the assistance of 
Professor T.A, Balogun, Head of Department of Teacher 
Education. As my external examiner at the University of Ife, 
he was naturally my choice as an adviser and guidian when I 
decided to enrol at the University of Ibadan. In his usual 
Calm and quiet way, he offered me the opportunity whose 
fruit I am reaping. He provided me with Valuable literature 
and his contributions in "Mathemagenic” and other works on 
biology textbooks weire my initial Sources of inspiration.
I also acknowledge with thanks the contributions of 
Dr* Diran Taiwo and Dr. O.J. Ehindero both of the University 
of Ife who on different occassions bailed me out of human 
frustrating problems during my Masters programme at Ife.
I am also grateful to Professor J.O. Akinboye for his 
consistent interest in my study; Dr. G.O.M. Onwu for his
UNIVERSITY OF IBADAN LIBRARY 
X
searching, meticulous and sometimes ’’disturbing” criticisms 
and Dr. U.O$ Egbugara for his valuable contributions.
I wish also to remember (sadly though) the advices, 
care and assistance of late Dr. T.A. Akintobi of the 
University of Ife who was a brother and guidian. It has 
pleased God to take away this kind and gentle helper who 
could not hurt a fly at an unripe age of 40. May his soul 
rest in peace (Amen).
I am indebted to a few more people who had rendered 
valuable services in the course of this study. Dr. Ferni 
Akintola and Mr. Ayo Akinbami had to sacrifice their time
and energy to sought-out the computer analysis. To them I am
very grateful.\ To my colleagues at University Press Limited 
particularly, Chief 0 . Bankole, Mr. Bola Adeleke, Mr. S.A. 
Adewuyi, Mr. A. Atulomah, Mr® Tosin AWoiaiu, Miss Titi 
Solaru, Mr. J.O. Taiwo and Mrs. F. Shinkaiye who helped in 
estimating the syllables in the textbooks used for the 
study, I extend my gratitude.
Thanks are also due to Mr. E.k . Oghenede who handled 
the typing of this thesis; Mr. F. Adeleye my partner in 
progress; and the schools, students, teachers, officials, 
authors and publishers who took part in the study.
UNIVERSITY OF IBADAN LIBRARY 
xi
I acknowledge the contribution of Kir. M.0„ Akinleye, 
Managing Director, University Press Ltd., Ibadan to my 
professional upbringing ih publishing. My family and me 
will remain eternal grateful for his continuing assistance
i
and guidiance. I wish to also place on record the assistance, 
moral support and advice of Ope-Oluwa Ogunkoya who was a 
valuable companion and helper at some distressing periods.
My parents, parents-iri-law, brothers, sisters and 
friends have all contributed in no small measure in the 
fulfilment of this long-sought-for ambition. They all 
deserve special mention and commendation for their support 
and assistances.
Lastly, I want to express my sincere thanks to my wife, 
*Bola and my son, 'Femi for providing an atmosphere conducive 
for an academic works They both bore the indohVfehiehces 
of a busy father and husband. Praise be to God (Amen).
UNIVERSITY OF IBADAN LIBRARY 
xii
CERTIFICATION
I certify that this work was Carried out by 
Mr, A.I, Adelekan in the Department of Teacher 
Education, University of Ibadan, Ibadan,
SUPERVISOR
MESHACH BOLAJI OGUNNIYI 
B,Sc. (Zaria), M.Sc.j Ph»D. (Wiscohsin) 
Senior Lecturer in Science Education 
Department of Teacher Education 
bnivetkity of Ibadan
IBADAN
NIGERIA
UNIVERSITY OF IBADAN LIBRARY 
xiii
TABLE OF CONTENTS
PAGE
ABSTRACT ................................ . ii
DEDICATION oooooooooooooooopooopooeoeoooopoeoooo vii
ACKNOWLEDGEMENTS .......... .............. viii
CERTIFICATION • oooooooooopocecooaoooeooooooeeooo xii
TABLE OF CONTENTS oooo6opo^e«oocioeooeooooooooaooooo xiii
REFERENCES .................... . .......... 238
APPENDICES opoooooooooo«o6ooo<»oooo«ooooooooqoooo 264
LIST OF FIGURES ............... ......... xvii
LIST OF TABLES ................................. xviii
abbreviations .................... ....... ...... xxvi
DEFINITION OF TERMS . ...... . xxvii
CHAPTERS
I IN TRODUCTION * o o o o » o oodoooOooooooooooA^ts 1
Background to the study a................. 1
Need f oir the study oooooooooooeoooooooo&oo 11
The Problem ............ . 13
y IPO t N e S 0 S Qooooeoaooooooooooccoooooooooooo 14
Scope Of the Study ooftooooeooooooooooooooo 14
Assumptions ............................ 16
Significance of the study ................. 16
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PAGE
Limitations of the study » ..... . . . . . . . . 19
CHAPTER
2. THEORETICAL FRAMEWORK AND REVIEW OF RELATED
LXTERATLJRE o o o o e o o o o o o o o o o o o o o o o o o o o o o o o o 20
Introduction . . . . . . . . . . . . . . . . . . .... ; . . . 20
Questions and learning . . . . . . . . . . . . . . . . . 24
The effects of technical terms, specimens, 
diagrams/pictures and practical exercises
on learning . ...... . .............c o o . . 39
Readability of textual materials 53
Summary and Conclusion......... ..... ......... 64
CHAPTER
3. RESEARCH METHODOLOGY .. ............... ..... . 65
RGS0cUTCt"l design o o o o o o e o b o o o o o o f e o o b o o o o b e 65
tiableS e o 4 b e d o o o o o o o o o o o o o o o o o o o « o 9 o o o 67
Sensitivity, internal and external validity 69
Instrumentation... .... ................ 73
General procedure e o o o o o o o o o o o o o o o o o o o o o 88
Tt*ie pilot Study o o o o e o o o o o o o o o o o o e o o e o o c i 92
CHAPTER
4o main study methodology „  .. ........... 104
Sample selection....... ..... 104
Instrumentation*o o o o o o o o o ^ o o o o o o o o e o © o o © 110
UNIVERSITY OF IBADAN LIBRARY 
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PAGE
i  P r O C G d U J T G  o o o o o o o c o o o o o o o o o o e o o o o e o o o o o  m *
Pre— treatment activities .0 0.0... 112
Treatment implementation and verification 113
Post-treatment events . ...... . .....c... 113
Observation in the field «.»........ 114
Analysis of data ..........   115
CHAPTER
So RESt)iTS: '■ .*/• TG....... *................  116
Hypothesis 1  .... ....... . „. „ „ 116
Hypothesis 2 0 0 0 0 0 0 0 0 0.0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0  ̂ 16V
Hypothesis 3 ......................   191
CHAPTER
6« DISCUSSION OF RESULTS4 CONCLUSION.IMPLICATIONS
AND, RECOMMENDATIONS * . * . . ..... . ... ... * . 199
Discussion of results .................. 199
Questioning styles relative to cognitive, 
affective and psychomotor performance of 
students ..... ..............     200
0
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PAGE
Defined technical terms, local specimens,
labelled diagrams/pictures, inquiry method
and challenging practical exercises
relative to students cognitive, affective
and psychomotor performances O.o.oooo.0.oo. 208
Readability of textual materials ........  2 2 2
Conclusion doo*oooooooodo°ooo400oaoo*aeoo°o 225
Implications ...........       229
Recommendations ...................   232
REFERENCES „ *..... ......................  238
APPENDICES
1. Readability Index ..... ...........o„oo 26%4
2* Communicational Strategies Survey 4 . . . . 269
3. Textbooks Analysis Index .oooo.o.ooa.ot. 2*78
4» Subjects Selectioh Test 283
5* Students' Attitudinal Test 0o.*0 0 0 . 0 0 0 306
6« Students’ Achievement Test ..........  311
7, Students' Psychomotor Test/Students'
Psychomotor Assessment Inventory t..... 326
8* Notes of Lesson .............   332
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LIST OF FIGURES
NO. TITLE PAGES
1 . Design Format 65
2 . Schematic representation of
research procedure. 91
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LIST OF TABLES
NO. • DESCRIPTION PAGES
1 . Design of Experimental Setting .oe«>°co.»° 66
2 « Students Psychomotor Assessment Inventory
(SPAI) e o o o o o o o o o o o o o o c o o o o o o o o o o o o o o o o o 86
3, Wahome (1979) Adapted Interpretation Data 100
4, Pre-treatment Sample Mean Score in Nine
Schools ................................ 108
5, Pre-treatment Sample Score Analysis in the 
¥ AThree Schools Selected .... ............ 109
6, Frequency and Percentage of Types of 
Questions Used in Four Biology Textbooks 117
7,i Frequency and Percentage of Questions by 
Position in Four Biology Textbooks ldfl
8 0 Summary of the Analysis of Variance of
Introductory, Contextual, Terminal, Factual, 
Leading and Probing Questions (Questioning 
Styles) in four Biology Textbooks „„„»o». 120
9 0 Summary of Tukey's a Posteriori procedure
on Introductory, Contextual, Terminal, 
Factual, Leading and Probing(Questioning 
Styles) in four Biology Textbooks 122
10. Frequency and Percentage of Technical 
terms Used in four Biology textbooks 124
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NO* DESCRIPTION PAGE
11. Summary of the Analysis of Variance of 
Status of technical terms Used in four 
Biology textbooks 126
1 2. Summary of Tukey's a Posteriori procedure 
on stgtus of technical terms used in the 
four Biology textbooks: Defined at first 
Occurrence} Dcfinod immediately after 
occurrence^ Defined later; Undefined 1L©
13. Frequency and percentage of specimen in 
the four Biology textbooks 0o.ooo..<>o. 130
14. Summary of the Analysis of Variance of 
lobai and fJon̂ -local Specimens in the 
four Biology textbooks .0 0oo».oooo..oo 131
15. Summary of Tukey's a posteriori procedure 
on local and non-local specimens in the
four Biology textbooks .............. 132 
16. Frequency and percentage of major themes 
in the four Biology textbooks ooooo.ooo.o** 134
17. Summary of the Analysis of Variance of 
major themes (Evolution; Ecology; Economic 
Importance; Inquiry; History; Knowledge
and world view in the four textbooks 137
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NO. DESCRIPTION PAGES
18* Summary of Tukey's a posteriori *
Procedure on major themes: Evolution, 
Ecology, Economic Importance Inquiry, 
History, Knowledge, ^orld*-view in the 
four Biology textbooks .... . ......... 139
19. Frequency and Percentage of Pictures in
the four Biology textbooks ............ ... 141
20. Frequency and Percentage of Diagrams in
the four Biology textbooks......... . 142
21. Summary of the Analysis of variance of
Diagrams and Pictures in the four Biology 
textbooksi ......... ............... . 144
22* Summary of Tukey*s a Posteri'dri Procedure on 
Diagrams and Picture in the four Biology 
textbooks.................................. 146
23* Frequency and Percentage of Practical
exercises in the four Biology textbooks..... 148
24. Summary of the Analysis of variance of 
Practical Exercises in the four Biology
textbooks 150
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NO. DESCRIPTION PAGES
25. Summary of Tukey’i s a Posterior;i Procedure 
on Practical Exercises in the four
Biology textbooks ......4................. 152
26. Frequency and Percentage of Physical 
Characteristics in the four Biology
textbooks ............................... 1 5^
27. Summary of the Analysi s of Vari ance of 
Physical Characteristics in the four
Biology textbooks...................... . 156
2 8. Summary of Tukey’s a Posteriori on Physical
Characteristics in t1he four Biology
textbooks. 158
29. Mean, Standard Deviation of Respondents iri
the Communicational Strategies Survey....  l60
30. Summary of the Analysis of Variance on 
Preferences of Authors, Publishers,
Ministry Officials, Teachers, and Students 
Relative to Comvnuni cat i onal Strategies
In Biology textbooks............. . 163
3 1. Summary of Tukey's a Posteriori Procedure on
Respondents Score in the Communicational 
Strategies Survey..... ......................  165
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NO. DESCRIPTION PAGES
32. Means, Standard Deviation and t-test of the
relative Effects of Leading questions on 
Cognitive performance of Experimental and 
Control Group Subjects,..,.......... ....... l68
33. Means, Standard Deviations and t-test of 
the relative effects of probing questions on
Cognitive Performance of experimental and 
Control group sub jects. . . . ................. 171
34. Means Standard Deviatiori. and t-test of the 
relative effects of Contextual questions on
Cognitive Performance of Experimental and
1
Control group subjects..,....... .......... 172
35. Means Standard Deviations and t-test of the 
Relative effects of Defined technical terms 
on cognitive Performance of Experimental
and Control group subjects. .  .... . 174
36. Means, Standard Deviations and t-test of the 
Relative effects of Local specimens on 
Cognitive Performance of Experimental
and Control group subjects............... . 175
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xxiil
NO. DESCRIPTION PAGES
3 7. Means, Standard deviations and t-test of the 
Relative effects of Labelled Diagrams and 
Pictures on Cognitive Performance of
Experimeatal and Control Grout) Subjects*... 177
3 8. Means, Standard Deviations and t-test of
the Relative Effects of Inquiry Method on 
Cognitive Performance of Experimental and 
Control group subjects......... . 178
39. Mean, Standard Deviations and t-test of the
Relative effect of Challenging Practical 
Exercises on Cognitive Performance bf 
Experimental and Contfbl group stabjects. .. . . 180
40. Means, Standard Deviations and t-test of 
the Relative effects on questioning styles 
on affective Performance of experimental
and Control Group Subjects.................. 181
41. Means, Standard Deviation and t-test of the 
Relative effects of Defined Technical
Terms on Affective Performance of Exoerimental 
and Control Group Subjects................... 183
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NO. DESCRIPTION PAGES
42. Means, Standard Deviation and t-test of
relative effects of local specimens on 
affective Performance of Experimental and 
Control group subjects. ........ . ......... l84
43. Means, Standard Deviations and t-test of
the Relative effects of Labelled diagrams 
and Pictures on affective Performance of 
Experiment and Control group subjects.... » l86
44. Means, Standard Deviations and t-test of the
Reldtive Effects of Inquiry Method on 
Affective Performance of Experimental and 
Control group subjects..... ............... 1 8 7
45. Meads, Standard Deviations and t-test of the 
Relative effects of Challenging Practical 
Exercises on affective Performance of 
Experimental and Control group subjects.... 189
46. Means, Standard Deviations and t-test of the 
Relative effects of Physical Characteristics 
on Affective Performance of Experimental
and Control group subjects............ . 190
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NO. DESCRIPTION PAGES
47. Means Standard Deviations and t-test of the 
Relative effects of Communicational Strate­
gies on Psychomotor Performance of 
experimental and control groun subjects.... 192
48. Means, Standard Deviations of Readability 
Scores for the four Biology textbooks... . 4. 19!)
49. Readability Value Intenretation of the 
four Biology textbooks (Using rfahome (1979) 
Interpretation Data)....................... 194
50. Summary of the Analysis of Variance oI f )the
four Biology textbooks Readability Values... 196
51. Summary of Tukey's a Posteriori Procedure 
on Readability values of the four Bioloj> gy
textbooks. . ......................... 197
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XXVI
ABBREVIATIONS
The following abbreviations have been used in the text 
of this thesis:
c - control group
w c S e S e Communicational strategies survey
E1 - Experimental Group 1
e 2 - Experimental Group 2
N .  S. - Not significant
R .  I e - Readability index
S - significant
S.A.T„ - students' Achievement Test
S.A.T.T. Students' Attitudinal Test
S.E.P *A. - science education programme for Africa
S.P.A.I. - students' psychomoter Assessment inventory
S.P.T. - Students’ psychomoter Test
S-S-T. - subjects selection Test
STAN - science Teachers Association of Nigeria
i c B o A o - Textbooks Analysis
W.A.E.C. - west African Examinations Council
> - Greater than
< - Less than
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XXVII
DEFINITIONS OF TERMS
in this study a number of terms have been used which
require operational definitions.
They are as follows;
Communicational strategies; A process, method or ways of planning, 
executing and giving information by verbal and /or 
non-verbal activities sufficiently meaningful to a recipiei 
in a way to elicit maximum response from the recipient.
Contextual Questions; Are those questions used within the meaning 
of the subject-matter being discussed or the textual 
material.
inquiry Theme; is concerned with the attempt directed at finding 
out more about a phenomenon, object, event or situation 
presented in a textual material or learning episode.
Leading Question; These are questions that are concerned with
guiding or directing the reader to an answer given later 
on in the text.
pictures and Diagrams; Are the illustrative two-dimensional 
drawings, sketch representation, photograph or visual 
images of an object, process or system used in the
textbooks
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xxviii
practical Exercises; These are practical exercises involving 
casual observation, setting up of an experiment by a 
student, group of students or the teacher in order to 
demonstrate a highly specialised knowledge or skill, 
probing Questions; These are questions that require the reader 
to give free expressions, personal opinions or an 
evaluative judgement.
Specimens; These are foreign or locally available organisms, 
which may be either preserved or living.
Technical Terms; Are biological terminologies which may be 
defined in the text or left undefined.
UNIVERSITY OF IBADAN LIBRARY 
CHAPTER ONE
INTRODUCTION
Background to the Study
Researchers in education have acknowledged the important 
role that books can play in the dissemination of knowledge.
Books are indispensable to most teachers and their students.
This is because books serve as the very point of contact 
between the curriculum proper and the actual learning materials. 
In other words, books are means to an end in the process of 
disseminating information in any particular field. Since the 
documentation in 1932 of, "The teaching of general science", 
by the Science Masters Association of Britain, there has been 
major reforms of science curricular materials in many European, 
Asiah and African Countries,
A cursory review of the history of science teaching in 
Africa would reveal a general awareness of the need to make 
science functional and relevant to the growing and challenging 
needs of developing economies, Ogunniyi (1978) identified that 
in the earlier stages in most African Countries, the science 
curricula was tn.rfche form of syllabuses of the different 
science subjects developed for examination purposes. It was 
assumed that certain aspects of the curriculum would grow, while 
others would die a natural death - a phenomenon akin to natural
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2
selection in the evolutionary process. The immediate conse­
quence of this strategy, was the clustering of the curricula 
with materials that presented an inadequate View of science. 
With the attainment of self-government and the concormi- 
nant realities and challenges in the 1960*s, many African 
countries began to examine the place of science and science 
teaching in the overall manpower development process. To 
tackle the problem of shortage in scientific manpower, several 
ministerial conferences were held. These include among others 
those held at Tenanarive (1962), Addis Ababa (1962) and Lagos 
(1974), A UNESCO Report (1974) of the Yaounde (1967) symposium 
acknowledged the efforts of many African governments at science 
planning, decision-making and co-ordination (Ogunniyi, 1986), 
Cessac*s (1963) survey of the status of science teaching 
in tropical Africa showed shortages in virtually every area of 
science teaching. The facilities were grossly inadequate. The 
laboratory assistants were in short supply. The laboratory 
conditions including the availability of electricity, water, 
gas,'apparatus etc, were below expectation. Apart from this 
broad survey, reports from various countries showed that sci . » 
science teaching in these countries "'.was of a poor 
quality (Weaver, 1964; Kalamanathan, 1970;
UNIVERSITY OF IBADAN LIBRARY 
3
Gilbert and Lovegrove, 1972; Ttelbo* 1975; Ogunniyi, 1977; 
Orisaseyi, 1977)a All these studies showed that the type of 
science being taught in Africa could not prepare students 
adequately for future careers in science. The implications 
of this state of affairs in a continent aspiring for scientific 
and technological development are self-evident and may not 
require further comments.
Recently, Yoloye and Bajah (1981) found that despite the 
significant efforts made at improving the status of science 
teaching, most African countries had not attained the ambitious 
target set at the 1961 Addis Ababa conference.
Ogunniyi (1982) has adduced some reasons for the deplorable 
status of science teaching in Africa. These include among 
others*
(i) the rapid increases in students population;
(ii) the acute shortage of funds and laboratory facilities 
characteristic of most consumership economy;
(iii) the shortage of trained science teachers and 
laboratory assistants;
(iv) the rapid transfer rate of teachers from one school 
to another or outside the classrooms;
/
UNIVERSITY OF IBADAN LIBRARY 
4
(v) the negative effects of external examinations, and 
Cvi) the rapidly changing socio-political and educational 
policies*
In spite of the sorbid state of affairs sketched above, 
various attempts have been made to improve the quality of 
science teaching in the schools* The present poor status of 
schools, science is a product of several decades of lack of 
curriculum planning. As stated earlier, the science curriculum 
was not perceived beyond the examination syllabuses, 'therefore, 
the overall aim of science education was totally missing.
But from the 1960*s efforts, the picture begun to change for 
the better.
According to Yoloye and Bajah (1981), the process of 
curriculum development is perhaps the most remarkable change 
that has taken place in the educational system of many African 
countries. However, the 1960 conference in Rehovolt, Israel - 
"The Curriculum Development of New States", and the 1961 
conference at the Massachusettes Institute of Technology,
U,S.A. served as the catalyst to curriculum development efforts 
in Science and Mathematics in Afrldah countries. It is 
generally accepted, however, that the 1966 conference in Kano,
UNIVERSITY OF IBADAN LIBRARY 
5
Nigeria which gave birth to the African Primary Science 
Programme could be regarded as the real watershed of curriculum 
development efforts in science in African countries0
In addition, it is worthy to note that several organisa­
tions like UNESCO, African Curriculum Organisation (A.C.O),
Ford Foundation and Rockefeller Foundation have taken active 
part in the development of new science curricula in Africa*
Other bodies that have aided the development of science curricu­
lum process in Africa include: the International Council 
of Associations for Science Education (ICASE), World Confedera­
tion of Organisations of the Teaching Profession (WCOTP), 
Commonwealth Fund for Technical Cooperation (CFTU), International 
Council of Scientific Unions (ICSU) and USAID* The World Bank 
has provided aids ranging from financial assistance, supply of 
laboratory equipment, textbooks and teaching aids, to that of 
trained teachers and instructors (Ogunniyi, 1986).
A significant aspect of science curriculum development in 
Africa has been the emergence of educational development UhitS 
and centres. These have beeh the generating focus of SCiehce 
curricula, textual materials* supportive instructional and 
teaching aids* Also, the role of national and international 
teachers association in science curriculum development has been
UNIVERSITY OF IBADAN LIBRARY 
6
significant* These various bodies include, the •
African Association for the Advancement of Science and Techno­
logy (AAAST), West African Association of Science Associations 
(WASA), West African Association of Science Teachers (WAAST), 
Forum of Africa Science Educators (FASE) and Science Teachers 
Association in various countries (Nwana, 1980)*
It is crucial to emphasize that the revolution in science 
curriculum development in the United Kingdom and U*S,A. has 
had a significant impact on science curriculum development 
in Africa. A comparison of the general principles and products 
of science curricula in these countries with those in Africa 
would easily reveal obvious similarities. Balogun (1978) and 
Ogunniyi (1986) have provided summaries of the said similari­
ties between the science curricula developed in the West and 
those developed in Africa.
As a result of curricular reforms in science, the 
Examining Bodies have begun to set questions compatible with 
newly developed science curricula. For example in Nigeria, 
a request was made in 1968 by the West African Examination 
Colincil (WAEC) to the Science teachers Association of Nigeria 
(STAN) for assistance in the review and improvement of WAEC. 
science syllabuses. Prior to this period, members of STAN
UNIVERSITY OF IBADAN LIBRARY 
7
had ViJ; id * -entified (STAN Newsletter, 1970) that if science 
subjects are taught with an enquiry approach, science would 
be able to contribute to the nation’s socio-economic development* 
I'he direct consequence of various major curriculum 
reforms alluded to above and the changes in the methods and the 
content of science that followed, have brought into focus the 
need for teachers to acquire new instructional skills and 
strategies* For instance, individualised instruction and 
learning, resource-based learning and mixed ability classes, 
demand that materials be used effectively by individuals or 
groups for the maximum benefit of individual pupils* Conse­
quently, researches in education have turned their attention 
to the form, content, communicational strategies, presentation, 
storage and retrieval of acquired scientific knowledge*
Uche (1979) observed that the most important means of 
obtaining vicarious experiences in science at the secondary 
school level was by reading* As students make progress, the 
learning and reading tasks become more challenging, ciffused, 
complex and abstract* With the tremendous increase in 
students population in Africa - especially Nigeria, and the 
attendant problems, it has become imperative to provide an
UNIVERSITY OF IBADAN LIBRARY 
8
adequate science education for a greater number of students 
rather than a selected few.
With the gradual emergence of textbooks as a predominant 
teaching aid, it is still possible and increasingly desirable 
for different teachers to approach their subjects in a 
creative manner. A close association of textbooks, schools 
and teachers can provide a dinstinct measure of freedom for 
individuals to choose and decide on the value and quality 
of instructional materials. Consequently, a relevant question 
is, "What are desirable qualities of a science textbook?1'
This study has been designed to attempt an answer to the 
crucial dimension of examining the effects of communicational 
strategies in some biology textbooks on high school students 
learning.
Lewy (197*7) asserts that textbooks must be prepared to 
meet and suit the needs, interests and abilities of a defined 
student population. McAllister (1971) had observed that in 
most novels, the themes chosen are largely too mature, the 
style too comtemplative, too philosophic and necessarily 
weighted with description. Priare (1970) had however accord­
ingly pointed out that it is important for writers and authors
UNIVERSITY OF IBADAN LIBRARY 
9
to identify the concepts, images and language that students 
best understand when conceptualising on a work meant for an 
age grade,.
One of the challenges facing educational practice, is 
how to meet the individual student’s needs, aspirations and 
Capacities* Bailey C 19t>2), observed that a textbook is 
usually judged on the basis of the facts it contains, the 
clarity of its exposition to beginners, the validity and the 
enthusiasm with which it presents results of science to 
students* In the same way, Major and Collete (1961) had 
indicated that textbooks should be written to the comprehension 
level of students for whom they are intended* In ascertaining 
the ingredients for a functional education, Thomas (1978) 
pointed out that the needs of students should be identified in 
line with the learner's capacities, interest and inherent 
differences*
In Nigeria, students rarely have a say in the choice of 
textbooks being used in the school* In such a setting, it 
is imperative to note the warning by McAllister (1971) when 
he pointed out that textbooks selection should be based on 
the fact that adolescents do not have the same perspective
UNIVERSITY OF IBADAN LIBRARY 
10
and experiential background as the adult* This is a crucial 
factor that has to be considered when a textbook is to be 
adopted for students*
; According.Y;  ' t11 o-j;  ' Ev. ahs (1•; j9 \ 7• 6), most teachers and students 
had come to regard printed words as infallible* In most 
classroom interactions, many teachers rely almost exclusively 
on textbooks to shape their instruction in science (Piltz, 
1961)* Consequently, as Gould (1977) pointed out, textbooks 
have remained ah indispensable teaching aid. Textbooks have 
been accepted as critical components of courses than contact 
with actual living materials, and they have successfully 
remained valuable sources of information for illustrations 
and as a descriptive guide.
The situation in most developing countries as Ogunniyi 
(1982) observed, is an over—dependence on textbooks. He 
ascribed this dependence to acute scarcity of laboratory 
facilities, the need to cover examination syllabuses and the 
fact that teachers are not sufficiently motivated to explore 
their environment.
With the great premium placed on textbooks as an indis­
pensable facilitator of learning, there has been recent efforts
UNIVERSITY OF IBADAN LIBRARY 
11
in the examination of biology textbooks used In Nigerian secondary
schools ■( % BX' als'"- og’ un, 1978; Ogunniyi, 1982). These studies have 
complimented other research efforts on textual materials 
analysis (Wahome, 1970; Yoloye, 1975; Uche, 1979; Jegede, 1982; 
Okpalla* 1982)* These studies have concentrated on the survey 
of biology textbooks in terms of their popularity and types 
in secondary schools. The findings of the studies warrant 
the need to determine empirically the quantitative effects of 
identified communicational strategies on students* learning.
Need for the Study
In the development of relevant and viable scientific 
knowledge, researches in science education have focussed on 
curriculum reforms and changes in the methods and the content 
b f school science. Other areas of interest include analyses 
of the quality and merit of textbooks and classroom textual 
reading materials as effective teaching aids (Priare; 1970$ 
McAllister, 1971; Lewy, 1977; Uche, 1979).
All these studies on textbooks have only isolated the 
qualitative merits of the materials in terms of their suita­
bility, rather than their quantitative impact on student 
learning. In other words, they have been concerned largely 
with the researchers’ point-of-view of the comprehensibility
UNIVERSITY OF IBADAN LIBRARY 
12
and adequacy of classroom reading materials rather than their 
direct effect oh student achievement in science.
Researchers in science education have also identified the 
need to have textbooks that are relevant to the needs, interest, 
experience and capacities of the individual child (Bailey, 1952; 
Major and Collete, 196i; McAllister, 1971; Thomas, 1978). 
Although the need for acceptable resource materials has been 
recognised, there seems to be ah equal need to ascertain 
emperically the advantages and difficulties associated with 
such resource materials.
Studies on science textbooks have isolated a number of 
factors critical to the quality or suitability of such text­
books. These include the length of the sentences, the type of 
style, questions, pictures, diagrams and other aspects of 
communication (Piltz, 1961; Evans, 1976; Gould, 1977; Balogun, 
1978; Ogunniyi, 1982). There is no doubt that all these 
studies have provided useful information about the quality of 
good biology textbooks. However, they have neglected the 
vital area of the direct impact of such textbooks on student 
achievement. This study has been designed to provide some
UNIVERSITY OF IBADAN LIBRARY 
13
information in this area®
The Problem
The aim of this investigation was to examine the relative 
effects of Selected communicational strategies in some biology 
textbooks oh high school students* learning. In pursuance of 
this objective, answers were sought to the following questions:
1® Are there differences in the frequency of question­
ing styles, technical terms, major themes, diagrams 
and pictures, specimens and practical exercises 
used in the four biology textbooks involved in 
this study?
2. Are there differences in the cognitive , aJ£ective
of
and psychomotor performances / three groups of 
high school students relative to certain communica- 
tiortal strategies viz: style of questioning, 
defined terms, lodal specimens, labelled diagrams 
and pictures, an inquiry method and challenging 
practical exercises?
3® Are there differences in the readability indices 
of the four biology textbooks: Mackean, Ewusie,
Stone and Cozens and STAN Biology used for this 
study?
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14
Research Hypotheses
In seeking answers to these questions, the following Null 
hypotheses were posited for testing:
Hypothesis 1 (Ho^): There is no significant difference in 
the frequency of questioning styles, technical terms, major 
themes, diagrams and pictures, specimens and practical 
exercises used by the four biology textbooks involved in the 
study0
Hypothesis 2 (Ho2)s There is no significant difference in the 
cognitive, affective and psychomotor performances of high 
school students exposed to selected communicational strategies 
such as styles of questioning, defined terms, local specimens, 
labelled diagrams and pictures, an inquiry method and challeng­
ing practical exercises and those not so exposed.
Hypothesis 3 (Hq )̂: Thebe is no significant difference in
I ....... .. I ■! n . l ■ — ■ i ....... . I l A m*
the readability indices of the four biology textbooks* Mackean, 
Ewusie, Stone and Cozens and STAN Biology used for the study. 
Scope of the Study
The study was limited to class Four biology students in 
secondary schools located in Ibadan. It involved an emperical 
determination of textbooks readability indices, an analysis
UNIVERSITY OF IBADAN LIBRARY 
lb
of communicational strategies in the selected biology text­
books, and the relative effects of the strategies on students* 
learning# The study did not examine the effects of mediating 
variables such as sex, home environment and teachers personality#
The main focus was to examine the relative effect of 
selected communicational strategies in four biology textbooks 
on the affective, cognitive and psychomotor domains of the 
students learning#
The survey on communicational strategies involved in the 
study was limited to producers and consumers of biology text­
books# All the respondents were resident in Ibadan#
The textbooks used in the study were limited to four: 
Mackean, Ewusie, Stone and Cozens, and STAN Biology. The 
first three were chosen on the basis of Balogun (1978) study 
that they were the most popular Biology textbooks in use 
amohcj sedohdaby fedhoois in Oyo State# STAN Biology was the 
fourth textbook used in the study, because of the national 
popularity and acceptability of STAN Integrated Science earlier 
published by STAN, and the likelihood of this textbook 
becoming a very popular one in Nigerian schools#
UNIVERSITY OF IBADAN LIBRARY 
16
assumptions
in carrying out this study, it was assumed that:
The identified communicationa1 strategies used in the 
experimental setting, will elicit the same responses from the 
::.dents as those strategies contained in the textbooks examined*
I. The students involved were representative of class four 
students in oyo state.
3. The textbooks are still or will be (as in the case of STAN 
Biology) popular in oyo state secondary schools.
4. The viewpoints of respondents involved in the communicationa1 
strategies survey are reflective of the respective groups 
involved in the study.
3. The practical lessons observed are reflective of the practical 
.assons in oyo state secondary schools.
Significance of the study
in an increasingly technological conscious society as ours, 
the need to find ways and means of equipping the learner with 
necessary scientific knowledge, skills and attitudes has become a 
-atter of urgent necessity, to cope with the challenges, 
researchers have focused on the determination of minimum scientific 
knowledge, needed for a functional and scientific'.conscious citizen 
(ivowi, 1983; ogunniyi, 1983; Abdullahi, 1983; okebukola, 1984;
UNIVERSITY OF IBADAN LIBRARY 
Vi
Clarinmoye, 1983; Shuaibu, 1983; Obanya 1983)#
Researches in science education have been greatly involved 
in determining the place of such things as the teaching 
methods, classroom organisation and interactional patterns, 
teachers and students attitudinal disposition, and psychomotor 
development, including examination of the relative effects of 
instructional facilities amongst others in the learning of 
science.
Good as many of these studies have been however, very 
little attention has been paid to the place of textual materials 
in the learning of science. This is not to say that researchers 
are not aware of the importance of textbooks to learning in an 
environment with scarce facilities, but rather that such 
awareness has not resulted in detailed empirical studies. Till 
date, only a few studies have been carried out in the area 
(Ogunniyi, 1982; Guthrie, 1972; Wahoure, 1979; Jegede, 1982; 
Qkpalla, 1972). This study is a follow-up of earlier studies.
It is an attempt to examine in detail, different aspects of 
the communicational strategies used in textual materials which 
hitherto have either not been examined at all,, or have been 
treated rather superficially.
UNIVERSITY OF IBADAN LIBRARY 
18
Balogun's (1978) determination of the relative popularity 
of biology textbooks, and Ogunniyi's (1982) analysis of the 
communicational strategies used in some biology textbooks, 
have provided the necessary stimulus and inspiration for this 
study.
An important aspect of the present study was to determine
the adequacy of seli ected b:iology textbooks in terms of the 
level of readability and comprehension for the intended 
readership. This entailed a critical analysis of the content 
and communicational strategies used to dissiminate the content. 
It is hoped that the viewpoints of the producers and 
consumers of the biology textbooks would shed some light on 
vital factors that make a textbook relevant and popular. It 
is also hoped that the findings of this study would provide 
useful information for teachers and researchers with respect 
to the relative values of the selected communicational 
strategies - especially as they affect learning in biology. 
Similarly, authors and publishers might find the outcomes 
useful and informative in the development of new biology 
textbooks in Nigeria,
UNIVERSITY OF IBADAN LIBRARY 
19
limitations of the study
The study had the following limitations:
1. within the six weeks experimental period, only a single 
teaching unit -NUTRITION- was taught. This of course places some 
constraints on the generalizability of the findings.
2. Because of the complexity of the communicationa1 strategies 
involved in the experimental setting, the number of items selected 
for each strategy in the SAT, SATT and SPT was limited.
3. with inadequate laboratory facilities and acute shortage of 
Oology teachers, the school authorities were unwilling to 
distrupt class schedules for experimental purposes. Invariably, 
the study was limited to intact classes.
4. The partic.i Dating teachers for the treatment and the control 
groups had an initial difficulty following the designed notes of 
lesson. to these teachers, the notes placed some limitations on 
their individual style of teaching, methodology, strategy and 
presentation.
5. The participating teachers also had the difficulty of 
applying the practical Test Assessment inventory (PTAI) during 
the collection of pretest data on practical skills. The difficult 
arose from the limitations posed to the individual teachers 
ability to assess the criteria laid out in the instrument.
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20
CHAPTER TWO
T£H E' ORETICAL FRAMEWOR%K  ■ AND ■ ■REVIEW OF
Related literature 
Introduction
This investigation deals with the relative effects of 
selected communicational strategies ih some biology text­
books on high school Students learning# In this chapter, 
an attempt has been made to discuss the studies Within a 
theoretical research Context# For most empirical studies, 
this is largely hot only a CohVention, but also a desirable 
format in Which a proper perspective can be easily discerned# 
tor this study* the temptation exist for one to see the
study as an invest' igation of instructional strategy per se«. . .  - . . . /
However, this study was concerned with determining the
qUallty arid tile pdtehtial of a group ot biology textbooks 
for meaningful study of biology# Another aspect of the 
study was to examine the relative effects of the communica­
tional strategies employed by the textbooks on achievement 
in biology*
For more than two decades, science educators had 
established that science teaching can be most effective 
within the framework of a process of inquiry method (Gagne,
UNIVERSITY OF IBADAN LIBRARY 
21
1965; Scott, 1966). With this awareness, researchers have 
been working on factors that can assist enquiry behaviour. 
Schwab (1962) and Suchman (1965) primarily ascertained that 
questions and questioning are good facilitators of an 
enquiry behaviour. Consequently, science educators have 
identified a dynamic relationship between questioning and 
inquiry behaviour (Bossing, 1962; Scott, 1966$ Scheriber,
1967).
As evident today, one of the current emphasis in science 
education is the presentation of school science as a forum 
of enquiry (Schwab, 1962; Ogunniyi, 1982). In other words, 
the enquiry approach has become a central theory of instru­
ction.
Related!  to an enquiry approach and sometimes used i :
interchahgebly is the discovery approach in science teaching.
However, researchers have been greatly divided as regards
the communicational strategy that can best promote discovery
teaching. In a rather general perspective, Wilson (1969)
played safe when he observed that the art of questioning
can generally be said to be the essence of discovery teaching.
What sort of questions normally envince, enquiry behaviour?
UNIVERSITY OF IBADAN LIBRARY 
Although there is no general consensus about this, most 
researchers agree that contextual, leading and probing 
questions facilitate enquiry behaviours (Stevens, 1912;
Gall, 1970; Rowe, 1974; Ogunniyi, 1981; Carrick, 1982)»
Research efforts have also yielded some results in 
ascertaining the merits and the demerits of other communi- 
cational strategies sUbh as technical terms, specimensf 
diagrams, themes and practical exercises in the effective 
dessimation of SCiehtific knowledge (Keirr, 1963; Evans,
1976; Ogunniyi^ 1982; 1983).
It is generally accepted that effective communication 
is an important factor in a teaching<-learhing situation. 
Central to this factor is the issue Of understanding and 
cotrtprehehsion* ThCse include such parameters aS value, 
nature and merit of a teacher's perSbHality, his experiences, 
qualification and competence. In addition to this are such 
factors as the instructional methods, learning environment 
and pupils attitudes.
But while the teaching method is crucial to learning, 
the varying and divergent instructional aids that compli­
ment verbal and nonverbal interactions are also essential.
UNIVERSITY OF IBADAN LIBRARY 
The learning aids play complimentary roles ih supporting 
other instructional strategies in ensuring that materials 
to be learned are made mote meaningful, relevant and 
practicable than they would have otherwise been*
With the realisation that books are easily the most 
common^ accessible and readily available instructional 
facility, it is crucial that we determine their potentials 
to the teaching*-learning process* It is not enough to know 
that textbooks are in abundant supply, but also to determine 
emperically that they are contributing to learning. The 
implication is that we Would be boncerned not only with the 
quantity, but also the quality of reading materials available 
to the teachers and learners.
Fry (1964) Was concerned about this issue. He stressed 
that the sel^dtidn of the right reading materials for pupils 
is one of the most crucial jobs of the teacher. If a 
teacher gives his students a reading material which are 
found difficult or incomprehensible, the students would 
soon become bored and lose interest in the reading material.
Some attempts have been made by a number of investigators 
to determine the readability of certain science textbooks.
UNIVERSITY OF IBADAN LIBRARY 
24
The assumption here is that a book with a bight readability 
index is likely to constitute a problem to the reader® In 
spite of the notable efforts made in this area, the results 
have been inconclusive. The disparity of viewpoints one 
encounters in the literature is a pointer to the need for 
more investigations in the area.
Apart from readability issues^ there is the need for 
more investigation on those parameters that have direct 
bearing on the desirability of textbooks as an instructional 
tool. Some of these parameters have been identified to
include the use of pictures and diagrams; intellectual
com' \petence, interest, values and previous knowledge of 
learners; classroom interactional patterns; features of print 
and the leVel of the language used. We shall examine these
I t
in order to identify areas needing further iriVestigatioh. 
Questions.and Learning
In most developing countries, there has been major 
curriculum reforms and changes in the educational system 
which has made it imperative for science teachers to consider 
viable alternative forms of classroom organisation and 
communication. Individual learning, resource-based
UNIVERSITY OF IBADAN LIBRARY 
25
2 ’
instructional modes and mixed ability classes warrant that 
learning materials be used in such a way that will benefit 
the learners*
An area that has received increased attention is the 
quality of questions used in the instructional process. As 
in Nigeria where tiany teachers rely almost exclusively on 
textbooks to shape their instruction (Piltz, 1961) , the import­
ance of textbooks as pointed out by Evans (1976) becomes even 
more obvibus when one realises that both teachers and pupils 
regard printed words as infallible. With the awareness of 
textbooks as a predominant teaching aid, it has become 
possible for teachers to approach their subjects in a variety 
of ways and to exploit the communicational strategies used in 
the teXtbodks to the advantage of sciende teaChihg (Uche, 1979).
Textbooks have grown to be accepted as critical components 
of courses than contact with actual living materials. Text­
books have become identified as the greatest source of infor­
mation for illustrating as well as providing a descriptive 
guide in its role as an indispensable aid in teaching and 
learning. As Gould (1977) indicated, textbooks are essential 
components of classroom interactions, and are important
UNIVERSITY OF IBADAN LIBRARY 
26
facilitators of scientific knowledge. The seeming over­
dependence on textbooks demand that science educators 
examine closely the values and merit of textbooks in 
promoting science teaching.
Questions have been recognised as an important integral 
component of science teaching. Balogun (1974) in his investi­
gation of the topography of learning control in a science 
subject, examined the use of questions as an orienting 
stimuli which create a set of inspection behaviour, self 
testing, self prompting in addition to other mediating >
process in learning. He further examined the location and 
frequency of questions as can be identified in some text­
books and enrichment books. From his findings, he reached 
the following conclusions:
(i) That adjunct questions in written instructional 
materials facilitate learning.
(ii) That adjunct questions when used in the management 
of learning has to operate within traditional 
problems of learning, individual differences, 
learning rates and motivation.
UNIVERSITY OF IBADAN LIBRARY 
27
(iii) That textbooks are a significant part of instruction. 
These assertions indicate that questions as facilitators 
of learning has to operate within the usual framework of 
personal and environmental variables.
Generally speaking, the use of questions as communica- 
tional strategies is as old as the Socratic method of teaching. 
Gall (1970) identified the classification systems on questions 
developed by Bloom (1956), Ascher (1961), Garner (1963),
Adams (1964), Clements (1964), Gallagher (1965), Moyer (1965), 
Sanders (1966), Guzak (1967), Pate and Bremer (1967) and 
Schreiber (1967), Using these Systems, he provided a schema 
whith shows the common cognitive elements between the 
various categories of questions in the system. He, however, 
found ^ioom*s (1956) questioning Category to be the most 
appropriate for science teaching out of all the categories 
analysed.
Broadly speaking, there are two main functions for 
questions in the educational process. First, we use them 
to create perceptual set, that is to create an orienting or 
attending response in the instructional process (De Cecco, 
1964). Second, we use them to evaluate the outcomes of 
instructional process.
UNIVERSITY OF IBADAN LIBRARY 
28
Nuthal^land Lawrence (1965) also enunciated a classi- 
ficatcry system for questions based on verbal actions,*
They found that the issue of direct and indirect modes — 
dor.inative and integrative patterns of teaching is involved 
in the use of question ih an instructional process. They 
established further that while the direct mode (e,g. lecture 
technique) minimises the students' freedom to Response, the 
indirect mode (e.g. teachers questions) maximizes students' 
response freedom.
However, central to the discussion of questions in 
textual materials is their relative position and types in
the instructional strategy. The different tj ypes of questions 
asked within the classroom setting vary widely with respect 
to their nature, scope and purpose.
Balbgun (1974), in his study of the topography of 
learning control pointed but that the nature Of questions 
asked in a science lesson, determines the kinds of operations 
the learner will employ and the level of thinking at which 
he will operate. Questions often times can be related to the 
logic of the content and the cognitive operations sought 
(Mushi, 1971; Elstgust, 1971; Savage, 1972).
UNIVERSITY OF IBADAN LIBRARY 
29
Usually, a question may be posed in the form of what, 
how and why? These questions may normally warrant certain 
verbal or non-verbal activities. Those activities may 
include the stating or demonstration of a given knowledge, 
skill or attitude.
Some researchers categorise questions into two groups; 
those that perform the psychological functions, and those that 
depend -on the type of explanation elicited. Nuthall and 
Lawrence (1965) also categorised questions in terms of 
explanation elicited into; sequential - procedural, causal 
explanations, teleological explanations and normative 
explanations. Bingham (1979) in his study had only came up 
with the division of questions that perform psychological 
functions as including; focussing, extending and lifting 
questions*
Science educators generally agree that the kind of 
questions teachers ask play an important role in the outcomes 
of science teaching. However, as Balogun (1974) observed, 
the quality and value of questions depend on the teacher's 
characteristics, experience, competence, adequacy of wait­
time for teachers response and the psycho-social environment
UNIVERSITY OF IBADAN LIBRARY 
36
of teaching. As Trowbridge (1972) asserted, for a teacher 
to use questions adequately, he must be a good listener, 
be able to percieve his students' learning difficulty fairly, 
maintain a good level of awareness of curbent issue in science 
teaching, and be capable of formulating challenging and 
appropriate questions.
Science educators have also focussed on questions 
within classroom reading materials, Ogunniyi (1982) in his
investigation on Nigeriian Biology textbooks grouped questions 
into; factual, rheotorical, leading and probing. Factual 
questions relate to soliciting direct identification or 
recall of facts, Rheotorical questions demand no answer, 
Leading questions are concerned with guiding or directing 
the reader to an answer; while probing questions require 
free expressions* perStohal opinions and evaluative judgement,
Carrick (1977) in her investigation of recent books 
published in Britain found that there was a prepounderance of 
factual questions, Lowery and Leonard (1978) examined the 
questioning styles in fcur 'tommonly used Biology textbooks 
in the United States, They also discovered that the books 
contained mostly factual questions. The findings in these
UNIVERSITY OF IBADAN LIBRARY 
31
studies are related to the fact that most science textbooks 
are prepared along a definite syllabus, and for a set-out 
examination*
Another aspect of questioning, deals with the matter 
of efficiency in terms of promoting learning* Gall (1970), 
Rowe (1974) and Carrick (1982) studies indicate #ucelnately 
that questions can be used to measure efficiency of an 
instructional strategy, promote learning of situations, 
serve as a measure of the relative merit of wait-time in 
the instructional process. Carrick (1982) ascertained that 
questions can have considerable influence on the logic, 
language and facts control* She further identified higher 
order questions (Leading and probing questions) as stimula­
tors of inqttdry behaviour. She, however, sounded a note of 
Warning that while fadtual questions ate capable of leading 
to higher order questions, their over-use can trivalise 
learning since they are capable of calling for bits and 
pieces of information.
Ogunniyi (1982) in his study of some widely used Biology 
textbooks, asserted that rather than the quantity of 
questions in a textbook, the quality and appropriateness of
UNIVERSITY OF IBADAN LIBRARY 
32
questions are the crucial issues in a learning process.
Pressey (1950) had earlier in his investigation on the 
role of questions also indicated that questions used as a 
review test are capable of serving didactic and diagnostic 
functions.
Furthermore, in their studies on the hole of questions 
in the teaching-learning episode, Rothkopf (1966, 1970),
Frase (1868, 1970) and Anderson (1970) ascertained that 
the inclusion of questions in written and instructional 
materials increased the amount of materials learnt from the 
textbooks.
Reinforcing this same point, Balogun (1974) had indicated 
that the way we use questions centre largely on the value 
they have for producing desirable changes in the students , 
behaviour. More precisely, Balogun (19*74) citing Frase (1970), 
pointed oilt that questions are capable of influencing learning 
through:
(a) Their position in a text.
(b) Their contiguity to related content.
(c) The type of questions used.
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In addition to identifying different types of questions, 
research efforts have also been directed to the use of 
questions in learning,, Ruthkopf (1965, 1966) and Frase (1967) 
pointed out that questions facilitate retention of specific 
and incidental information when short tests are included in 
prose materials®
In addition, Balogun (1974) pointed out that questions 
that come after prose passages are most effective for specific 
and general retention. According to him, pre-questioning 
limit the range of attentive behaviour, while post-questioning 
tend to lead to general orientation. He further explained 
that mathemagenic responses result when Unrelated questions 
precede a passage.
Apart from the usage of various type of questions, the 
positiori of qiiestions in the textual materials has been folirid 
to be very crucial. Ogunniyi (1982) using a modified version 
of the scheme developed by Lowery and Leonard (1978) catego­
rised the position of questions in a textbook as introductory, 
contextual, terminal and captional. An introductory question 
is that placed at the beginning of a paragraph to arouse 
interest or curiosity about a subject-matter. A terminal
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34
question occurs at the end of a paragraph or section, and 
it is often used to evaluate the level of understanding of 
a reader, A captional question is used in reference to a 
topic, heading, section, table or graph; while a contextual 
question is used within the body of the prose material.
In their analysis of widely used biology textbooks
in America, Lowery and Leonard (1978) found that questions
placed at the beginning or end of a parag.raph stimulated 
better performance of students, Carrick (1982) and Ogunniyi 
(1981, 1982, 1983) on the other hand, found that captional 
questions when used as advance organisers tend to encourage 
a reader to speculate rather than take facts at their face 
value. They contended further that contextual questions 
were valuable and useful to the understanding of scientific 
concepts• „
Host science educators agree that the crucial factor 
central to the isfeue of questioning ih science teaching has 
to do with the adequacy and relevance of a given question in 
an instructional material. When the questions used are 
appropriately placed and/or relate specifically to the issue 
at stake, they tend to stimulate curiosity and to hold the
UNIVERSITY OF IBADAN LIBRARY 
35
readers' interest and attention with respect to the subject 
matter under consideration (Balogun, 1974; Ogunniyi, 1982; 
Carrick, 1982)«
A most significant dimension to questions in learning 
that need be discussed is the merit of questions as an 
arousal stimuli,, Skinner (1937, 1953) recognised that qu.- stior.r. 
questions provide a transition from the use of structured 
information for mediating process in learning to the use of 
structured information for such functions as thematic probesc 
He noted that questions of the specific interrogation type, 
function as thematic probfes which induce epistemic curiosity,,
Berlyne (1954) asserted that questions facilitate 
approach, act as receptor adjustment and are capable of 
manipulating the environment so as to perceive relevant 
stimuli observed. He further observed that questions can 
elicit trial and error learning in addition to insightful 
restructuring and curiosity. Berlyne (1954) went on to 
provide factors that has to be provided for questions to 
arouse curiosity. The factors include: the degree of the 
conflict, that is the number of competing tendencies and the 
degree of incompatibility - that is questions that give the 
most surprise. He concluded that while pre-questioning
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36
arouse curiosity, questions with incompatibility of concepts, 
are capable of arousing more curiosity.
While Kubis (1948) pointed out that questions are 
capable of operating as an effective arousal stimuli,
'•atkin and Stahler (1969) found that adjunct questions are 
the most adequate in improving performance of students. 
Putting the fact more succinately, Rothkopf (1966) asserted 
that test-like questions presented after reading a text 
material have specific and general facilitative effects on 
post-reading performance. He observed that questions placed 
before the text material produced only question-specific 
facilitative effects. Bruning (1978) on the other hand, 
indicated that infrequent testing within a learning material 
nay be an important environmental control of positive 
learning behaviours.
Examining further the issue of questions as orienting 
stimuli, Balogun (1974) also indicated that questions like 
other thematic probes induce drive-producing meaning 
responses as well as learned (conceptual) conflicts and 
efforts after meaning. He further asserted that questions 
have a facilitative effect on learning from written 
materials.
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37
It is impertant to examine a significant study on 
questions and learning carried out much earlier by Wash- 
burne (1929)* This study more or less summarises basic 
views earlier expressed in the studies so far considered,, 
Washburne (1929), sets out to investigate three issues:
(i) The effect of questions on recall of facts and 
the ability to make generalisations*
(ii) The issue of whether questions should be grouped 
at the end, beginning or scattered throughout the 
text material*
(iii) Whether the type and the placement of questions 
have any effect on children of different grades, 
ages, sex and abilities*
Washburne (1929) found that the best location of questions 
was at the beginning of a text material, and that questions 
at the end of a text material were less effective* He, 
however, pointed out that cjtiestions placed at the end of a 
paragraph aided understanding of the related parts*
Frase, Patrick and Sbhumer (1970) in their investigation 
of the effect of questions, their position and frequency 
on learning from a text material have added the aspect of
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38
Motivation to questioning* They in fact looked at the 
position of questions with respect to the beginning, the 
end and those interspersed within a textual material* From 
their study* they found th§t the frequency and the position 
of questions interspersed within the text, influenced the 
learning of a text material* By further introducing--an
element of moti.i vation, they found that motivational factors 
are dependent on such other factors as position and frequency 
of questions, the relevance of the learning items and other 
incidental learning items* Their investigation also showed 
that the frequency of questions contributed to the influence 
of motivational effects, and that the contiguity of questions 
was a primary factor in the control of text learning.
These studies have indicated that questions have 
facilitative effects on learning* The relative merit to 
iteaî hiriq that have been identified, relate to the type of 
qtiestions^ their* positioh Within the text, and their use 
particularly as an orienting stimuli*
With respect to type, most of the studies have concen­
trated on the predominant factual questions, with lesser 
attention paid to leading and probing questions. Other 
areas of interest include the issue of pre-testing, post-
UNIVERSITY OF IBADAN LIBRARY 
39
testing and terminal questions. But till date, little 
has been done in highlighting more evidently the role of 
introductory, captional and contextual questions in a 
textual material. Consequently, it could be observed that 
the paucity of information in this area warrant further 
investigation.
The effect of Technical Terms. Specimens. Diaqrams/Pictures 
and Practical Exercises on Learning
Other areas of research interest relative to textual 
materials have been the status of pictures/diagrams, the age 
and grade of learners, the learner capability and previous 
knowledge, features of text print, technical terms, specimen, 
complexity of major themes and the practical exercises that 
have bearings on students' learning. Various studies have 
been carried out to determine the relative effectiveness 
and appropriateness of these strategies with respect to 
learning ahd cohipJrehehsion of written materials.
Technical terms
Biology is one of those science subjects with complex 
and difficult technical terms and nomenclature „ Biological 
nomenclature are often in the latinised form with ^sometimes 
a chain of generic, subgeneric and specific names, which
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are capable of constituting learning difficulties*
Ogunniyi (1982) categorised technical terms in terms 
of those that are defined at their first occurrence; those 
defined immediately after they occur in the text; those 
defined later on in the text; and those that are not defined 
at all*
Evans (1976) had earlier in his study of technical 
vocabularies in biology textbooks, found that the best 
place to emphasize a technical term is at the point of first 
occurrence* He contended that since explanations in 
eliciting meaning involve the use of a language, writers 
should be aware of their choice of the descriptive terms 
in that language* He observed further, that the complexity 
Of a given language used Could create the problem of ambiguity 
To Evans therefore, appropriate definitions should be used 
in describing technical terms* The reason for this is quite 
obvious* The choice of definitions in deeCrlbihg^ Could 
clarify or becloud the understanding of what is read* The 
choice of appropriate definitions supports Ogunniyi*s (1982) 
suggestion that technical terms in biology should be clearly 
unambigous, forming as dinstinctly as possible a precise
UNIVERSITY OF IBADAN LIBRARY 
41
0
instrument for communicating scientific information.
In his analysis of the communicational strategies in 
Nigerian biology textbooks, Ogunniyi (1982) suggested that 
technical terms should be defined as soon as they occur so 
as to facilitate reading and understanding of the textual 
materials. To him, a biology textbook with a preponderance o 
of undefined technical terms is foreign to an uninitiated 
learner.
Putting the issue in yet another perspective, Carrick 
(1982) in her examination of recently published biology 
teXtbookfcin Britain observed that defining, developing and 
illustrating the points in a textbook rule out dogmatism, 
make the material interesting to read and readily comprehen­
sible*
Although these studies Recognised that technical terms 
When Clearly defined are desirable fob science teaching, 
they betve not provided much information about the relative 
importance of technical terms defined at different points 
within the reading material. There is an urgent need to 
quantify the relative merit to learning of technical terms 
defined immediately they occur; those defined at first
UNIVERSITY OF IBADAN LIBRARY 
42
occurrence; those defined later and for comparison, the 
value of undefined technical terms*
Specimen
Biology as a science subject deals with a vast array 
of flora and fauna ranging from microscopic to extrerhel^ 
large organisms* These organisms or their parts under 
close study are known as specimens* A given specimen bay 
be alive or preserved in some chemical for future study*
It is not always that real materials are available* At 
times, only a model of a specimen is all that can be obtained*
Ogunniyi (1982) has classified specimens in terms of 
foreign and local varieties* The former are not endemic to 
the region where it is being studied, while the later thrive 
within the local environment of the learner* From his 
analysis, he found that most Nigerian biology textbooks 
use specimens that can be obtained locally* The associated 
advantages of locally existing specimens in terms of 
enhancihg familiarity and hence Understanding among learners 
cannot be over—emphasised. Furthermore, Ogunniyi (1982) 
observed that although the books were written by foreigners 
and nationals, the former having lived long in Africa,
UNIVERSITY OF IBADAN LIBRARY 
43
A2
seemed to be quite familiar with the local specimens as 
the nationals. In other words, the textbooks analysed 
were relatively well stuffed with local specimens. Less 
than 5 percent of the specimen could be regarded foreign.
Presently, there is a new trend of authorship in 
Nigeria, We now have a situation where experienced Nigerian 
teachers have been writing books, and others now serve as 
editorial board members, which are otherwise recognised in 
some publishing hoUses as co-authors or contributors for 
biology textbooks specifically prepared for West African 
English speaking schools. This has made it possible for 
teachers to avail themfeeives of existing but unrecognised 
community-based specimens that can be used in biology 
teaching. As evidenced in the new "STAN Biology” written 
by STAN, the textbook has hot only facilitated the learning 
of biological concepts and principles, but has also made 
the subject matter more lively, interesting and relevant. 
Pictures and Diagrams
Science educators are fully agreed about the positive 
role of pictures and diagrams to comprehension of a written 
material. Pictures and diagrams can through their form,
UNIVERSITY OF IBADAN LIBRARY 
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44
clarity, colour and adequacy enhance Communication and 
compliment written and verbal instructions (Ogunniyi, 1982)* 
Good pictures ahd diagrams Can be used to convey the meaning 
of concepts and principles which Would otherwise have been 
distorted by language.
Researchers have ascertained the effect of pictures and 
diagrams on learning. Reid and Miller (1980) investigated 
the perception of pupils with respect to biological pictures, 
and their implication for Comprehension and understanding 
of concepts and principles* Cehtral to their study, WaS the 
use of colour in pictures and diagrams* They found that the 
use of colour in biology textbooks is Capable of enhancing 
the students power of observation, especially ih students 
With average ability* They, however* stated that although 
the use of colour in pictures and diagrams of biology
k ! ■
ohal skills, they
are capable of serving as destractors to other students.
With respect to coloured pictures and diagrams of 
higher complexity, Reid and Miller (1980) discovered that 
the effect of colour in enhancing students' observational 
capacity was limited by the ability range of the students.
UNIVERSITY OF IBADAN LIBRARY 
45
In other words, the ability to derive meaning from a 
coloured picture or diagram was dependent on the age and 
ability of the learner#
Another dimension of pictures and diagrams that has 
been examined, relate to their use as advance organisers,, 
Egbugara (1983) investigated the relative effects of oral, 
written and pictorial organisers on students achievement in 
physics# He found that a combination of written and pictorial 
organisers were more effective in h* enhancing students
achievement than written materials alone,,
However, Ogunniyi (1982) had earlier pointed out that 
pictorial representations were capable of facilitating 
learning# He emphasised that the Quality rather than the 
quantity of diagrams and pictures was the crucial factor in 
learning#
Science educators generally agree on two categories of 
pictures and diagrams; the labelled and those not labelled# 
Ogunniyi (1982) asserted that learning in biology can be 
exceedingly boring and uninteresting to the students when 
they are devoid of good and clear pictures or diagrams# A 
criterion of good pictures and diagrams he noted, is that
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5
46
they should be well labelled* A well labelled diagram he 
further remarked is an indispensable memory aid and compre­
hension guide, whereas an unlabelled diagram or picture 
have little use to the reader unless they are adequately 
described. A good diagram could conveniently replace a 
long portion of written material*
The merit of pictures and diagrams to learning have 
also been investigated by other researchers. For example, 
Etfans (1976) in his study of technical vocabularies in 
Biology textbooks recognised the fact that descriptions as 
a way of explaining an anatomical and morphological feature 
is capable of distorting learning. He concluded that a 
long and detailed description Can neither be an adequate 
substitute, nor a viable alternative to a clearly labelled 
diagram.
Putting the merit of pictures and diagrams in obvious 
words, Ogunniyi (19821 asserted that the foreigness of a 
textbook should perhaps not be construed only in terms of 
their country of origin, or the authors country of domicile? 
but rather in terms of the communicational gap that has been 
inadvertently created by inadequate or poorly labelled
UNIVERSITY OF IBADAN LIBRARY 
47
C
pictures and diagrams*
In spite of the notable research studies alluded to 
above, more information is still needed with respect to the 
relative merit or demerit of pictures and diagrams. The 
findings of such studies would further enhance our under­
standing about the role of pictures and diagrams in biology 
teaching*
Major Themes
Science educators have also recognised the value and 
merit of central themes in the presentation of scientific 
facts and knowledge*
Themes in biology teaching are varied 1 and many. How­
ever, Ogunniyi (1982) in his analysis of cotnmunicatiohal 
strategies used in Nigerian biology textbooks found that the 
frequently occuring themes were; evolution, history, ecology, 
inquiry, economic importance and knowledge* An evolutionary 
theme refers to origin., growth, development and adaptability 
of biological systems in response to ecological and environ­
mental changes* Historical themes he remarked, relate to 
biological stories of how a concept, generalisation, process 
or skills were discovered; an ecological theme deals with
*A» • -f n
UNIVERSITY OF IBADAN LIBRARY 
48
.7
the study of the inter-relationship of organisms and their 
environment. An inquiry theme is concerned with an attempt 
directed at finding out more about a phenomenon, object, 
event or situation, while economic importance as a theme 
relates to the benefit to man and the society of a given
biologi5; cal . s• y; stem, : •knowledge, skill or process. To him, 
knowledge relates to factual presentation of biological 
principles and facts. This Categorisation of themes look 
comprehensive, but does not seem to include all the themes 
that can be found in biology textbooks. The publication of 
STAN Biology for instance, demand the inclusion of "world- 
view" as a theme of importance in Nigerian schools central 
to teaching and learning of biology. It has been made a 
major theme in this textbook as a recognition of societal 
values and aspirations, including cultural beliefs in the 
presentation of biological facts, concepts and principles.
For the past two decades, the emphasize in science 
education has been the presentation of school science as a 
form of inqury rather than a dogma. De Marris (1965) in 
his study on the nature of science content, indicated that 
historical presentation of learning materials enhances
UNIVERSITY OF IBADAN LIBRARY 
49
student understanding of biological teaching* In addition, 
Cooper and Petrosky (1974) in their investigation of students 
perception of science as a subject, had found that science as 
a subject and a way of inquiry was of great interest to 
students*
Ogunniyi (1982) had further observed that there is 
the need for more efforts at improving and impacting 
relevant scientific knowledge using such themes as ecology 
and economic importance because of recent environmental 
problems facing the fauna and the flora of most African 
countries* He further cautioned that with respect to 
evolution, the theme should be presented in a less dogmatic 
manner* This is because of the importance attached to 
religion as a tradition and a way of life in many traditional 
African societies* It should be noted that the African 
cultural background, rest in the belief of a Supreme God* 
other divinities and forces which can not be completely 
neglected in the presentation of biological principles* 
Despite the importance attached to the teaching of themes, 
however, there is'paocity of research findings in the area*
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50
Practical Exercises
Studies in science education, have been directed at 
identifying the nature, and types of classroom practical 
exercises that can promote science teaching. In an apparent 
realisation of this fact, Summer (1950) stated that centuries 
of deductive reasoning of> the past, had failed to produce 
the Utilitarian results when compared to a few decades of 
experimental methods»
In his work on the place of practical work in school 
science course, Rail (1963) enumerated that the over-all 
teaching of science can be broad-based if approached through 
experimentation. In the same way, Hurd (1969) found a positive 
correlation between the performance of students and the use 
of laboratory exercises.
The findings of these studies tend to suggest the fact 
that practical exercises can promote effective teaching and 
learning of science. In his study of the value of practical 
work in teaching, Holt (1969) identified that the main goal 
of practical exercises should be the provision of adequate 
opportunities for students to investigate (Schwab, 1962).
Further studies by Tamir (1978), involving the determina­
tion of ̂inquiry and curiosity in the laboratory, revealed that
UNIVERSITY OF IBADAN LIBRARY 
51
laboratory exercises were capable of facilitating the develop­
ment of scientific skills and attitudes.
Schunke (1979) in his investigation of curriculum and 
choice of task organisation, pointed out that particularly 
within a cooperative framework, there is an improvement in 
learning when psychomotor skills are used in teaching.
Ogunniyi (1983), also reiterated the fact that laboratory 
exercises provide students with the opportunity to study 
abstract concepts and generalisations through the medium of 
concrete materials. When practical exercises are appropriately 
chosen and well executed with locally available materials, 
they constitute an indispensable entity to the development 
of science teaching and learning (Blan, 1954; Schwab, 1962; 
Ansubel, 1968).
It is imperative at this point to consider researchers 
categorisation of practical exercises. Ogunniyi (1982) in 
his analysis of communicational strategies used in Nigerian 
biology textbooks, categorised practical exercises found in 
the textbooks to; simple, specific, general and challenging.
To him, a simple experiment is concerned with a casual obser­
vation; a specific experiment requires the learner to carry
UNIVERSITY OF IBADAN LIBRARY 
52
out individual laboratory or field work that may involve 
the use of equipment such as the hand lens and microscopes 
to study an organism, process or anatomical feature. A 
general practical work he noted involves a large group of 
students or the whole class in ah experiment or in a project 
for example, an ecological study of a pond. He further 
noted that challenging practical exercises involve the 
setting up of ah experiment by a student, group of students 
or the teacher to demonstrate a highly specialised knowledge 
or skill.
TEtese findings and categorisation can further be viewed 
in terms of their relative merit to learning and teaching in 
biology* Ansubel (1968) had emphasised that practical 
exercises are crucial to the development of a child's 
Cognitive ability.
Enumerating further the merit of practical exercises to 
learning, Ogunniyi (1982) in his analysis noted that a 
meaningful practical exercise should permit students an easy 
access and opportunity to have direct contact with the 
learning material. He further pointed out that while 
students in the lower forms could benefit from simple and
UNIVERSITY OF IBADAN LIBRARY 
53
specific practical exercises, the students in the higher 
forms should be exposed to challenging practical exercises 
that are capable of provoking curiosity and a search for
h; • !
valid evidences in scientific activities.
These studies reviewed above have shown that when 
practical exercises are well-planned, prepared, and adequately 
executed, they do contribute positively to the teaching 
and learning of science. It is, however, desirable to find 
out more about the relevance or merit of various types of 
practical exercises to learning. The application of varying 
types of practical exercises using locally improvised 
material might not only make biology teaching meaningful, 
but also relevant to the needs of the learner.
Readability of Textual Materials
The readability indices determination of textbooks has 
been an area of interest to educators in an attempt to 
ascertain the comprehensibility of reading materials. 
Generally, readability has been defined by educators as the 
relative ease at which people can respond in various ways 
to passages of written prose. Gilland (1972) and Yoloye 
(1975) recognised three important dimensions of readability.
UNIVERSITY OF IBADAN LIBRARY 
54
These are: comprehension, fluency and interest,, Uche (1979) 
identified other dimensions of readability such as the 
culture, reader’s interest, reading speed, recall of passage, 
proportion of ahswered questions and the comprehensibility of 
the material.
The issue of readability is particularly concerned with 
providing the right textbooks for the students. Since 1939, 
researchers have been concerned with formulating adequate 
readability formulae for ascertaining the comprehensibility 
of classroom reading materials. Most of the formulae have 
been developed to determine the quality control of communica­
tion effectiveness. The focus has been in the area of 
vocabulary, sentence structure and human interest.
Although there are many readability formulae in use, 
the weakhesses of most of them as encountered in literature 
reviews, suggest a cautions approach in selecting which 
formula one uses for a given study. For instance, the reada­
bility formulae developed by Flesch in 1943 was criticised 
by Dale-Chall (1948) as being very cumbersome to use. On 
the other hand, Flesch (1943) had earlier stated that Lorges 
(1939; 1944, 1951) formulae could not discriminate above the
UNIVERSITY OF IBADAN LIBRARY 
8th grade« In the same vein, Yoloye (1975), indicated that 
Dale—Chall (1948) formulae gave unnecessary heavy weighting 
to word difficulty,,
In addition, the formulae developed by Morris and 
Halverson (1938), Gunning (1952) and McLaughin (1969) have 
been variously driticised for been too cumbersome to use; 
poor discriminative index for pupils with mixed ability and 
for subjects with technical terms. In the attempt at 
taking care of his predecessors inadequacies, Taylor (1953) 
developed the "close readability structure" procedure. In 
this procedure, comprehension difficulty is measured using 
multiple items. Using some of these formulae or their 
modified version, researchers have carried out studies to 
determine the comprehensibility of reading materials.
Yoloye (1975) carried out an investigation on the 
reading levels of pupils and teachers using the Nelson-Denny 
test. The test was administered to randomly chosen samples 
of two schools in which the African Primary Science Project 
(APSP) curriculum material was used. He found that five of 
the eight textbooks in use had readability indices of 4.83 
or higher. When compared to the level of understanding of
UNIVERSITY OF IBADAN LIBRARY 
56
Nigerian pupils, Yoloye (1975) ascertained that a typical 
Nigerian primairy school pupil will have difficulty with the 
materialSo
Yoloye (1975) ascebtion could be thue bearing in mind 
the historical, cultural and educatiohal development of most 
African countries# With their Anglophone or Francophone 
background, most Africah countries and barticularly those 
tHat participated in the 1965 Kano Cohfebence which gave birth 
to the APSP, have comparable educational development. But 
this should not be takeh on the surface Considerihg the is 
issue of cultural variations which are also crucial to 
readability determination.
Vsing the Dale-dhall (1948) formulae* Yoloye (1975) also 
determined the readability indices for the Nigeridn Secondary 
Schools Science Programme (NSSSP) and the Social Studies 
Programme of Aiyetoro Comprehensive High School, He found 
that most Form I students and fity percent of Form II students 
in the secondary schools would experience difficulty in 
comprehending the materials. He also found that while twenty- 
five percent would have comprehension difficulty in Chemistry 
among Form III students, more than twenty-five of the same
UNIVERSITY OF IBADAN LIBRARY 
57
group will encounter greater difficulty in Biology*
As Yoloye (1975), rightly pointed out, the readability 
indices vary with age and level of intellectual development* 
The interpretiation for the primary school level would 
certainly be different from the secondary school level* This 
is because the conceptual emphasis of the secondary school 
science tend to contain more technical words and consequently 
raising the difficulty levels of the reading material than
would be encountered at the primary school level* This
|
becomes even more obvious when the readability formulae 
used include the notion of "difficult words".
Theria has been other readability studies before and after 
Yoloye (1975) studies which have attempted to determine the 
comprehension of the reading speed of ptipils* Chapman- 
Taylor (1965) carried oUt an investigation on the reading 
difficulties of 136 First Year undergraduates in Arts and 
Economics at the University of Ibadan* He found that the 
Nigerian students were comparable in all respects with their 
Australian counterparts. The only difference was in the speed 
of comprehension where the Nigerian students were found to be 
inferior to their Australian counterparts. This is an
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3
58
Indication that reading speed and comprehension may be 
culture—bound and related to the technological development 
of the society. Consequently, in one's choice of a reada­
bility formulae, this fact should be considered,
McKillop and Yoloye (1972) also investigated the reading 
difficulties of 92 randomly chosen undergraduates of Arts, 
Science and Social Sciences at the University of Ibadan,
They found the University of Ibadan undergraduates to be 
significantly inferior to their American counterparts 
especially in the area of comprehension and speed.
The variation in those findings can be escribed to the 
level of educational development in the different countries. 
With her growing technology, the American undergraduates has 
a more enriched environment when compared to his Nigerian 
colleague living in a predominant traditional culture.
As would be disfcussed later, Wahome (1979), Jfegede 
(1982), Okpalid (1982) who had examined the readability of 
chemistry, biology and physics textbooks respectively, have 
found that the textbook in these areas (which are all 
European-oriented), would definitely create reading difficulty 
for their desired readership. Perhaps the issue can not be
UNIVERSITY OF IBADAN LIBRARY 
59
ascribed to the traditional culture,, There seems to be a 
clear indication of relevance and need* The findings of 
Guthria (1972) and Carrick (1978) of science textbooks 
used in British schools indicated that the textbooks were 
adequate for the pupils. This is because the British 
textbooks were written to meet the needs of the learners in 
an education setting relevant to societal values.
As earlier mentioned, the major issue in readability 
determination has been the limitation^ of readability ■ >: 
formulae in use; Consequently, researchers have attempted 
to provide additional explanation for the differences in 
students4 comprehension, abilities, ahd reading speed in 
addition to other deductions derivable from estimated 
readability indices*
It is however crucial to examine more studies on 
readability deteHrlihatiori* ahd isolate factors thsit c§h 
assist the comprehension of a science reading material.
Okpalla (1982) using Flesch’s (1948) formula, examined 
the readability of physics textbooks used in Nigerian 
secondary schools. From his findings, he concluded that 
the difficulty level often assumed for a textbook has to be
UNIVERSITY OF IBADAN LIBRARY 
60
carefully estimated., Since sample pages are considered, 
he found that there are wide variations in the difficulty 
level of most of the pages in the physics textbooks. Hence 
he concluded that a text that may be considered readable on 
certain topics may not be easily understood on other topics. 
Another issue of significance, is the nature of reada­
bility formulae and the nature of science teaching, Yoloye 
(1975),hOkpalla (1982)» Ogunniyi (1982) had identified that 
most readability formulae are inadequate*predictors of some 
elements critical to comprehension. The identified elements 
include such things as illustrations, graphs, and diagrams 
in addition to characters of print of science textbooks.
As earlier pointed out, Wahome (1979), Uche (1979), 
Jegede (1982), Okpalla (1982) identified that there are 
varying difficulty levels associated with different grades of 
pupils. The Chemistry, Biology and Physics textbooks 
examined by these researchers respectively, were found to be 
unsuitable for Form Three pupils, but adequate for Forms Four 
and Five students.
Three reasons could be adduced for these differences:
(i) Physics, Chemistry and Biology textbooks are 
specifically prepared for West African School
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61
Certificate Examination. This is an examination 
that is largely relevant to the needs of Forms 
Four and Five students rather than Form Three 
students.
(ii) The relatively higher cognitive capacities of 
Forms Four and Five students.
(iii) The language competence of Form® Four and Five 
students is probably greater than that of Form 
Three students.
It should however, be noted, that language as an entity 
of culture has the intellectual and socio-cultural dimensions, 
in addition to the status of the learner* s previous knowledge. 
It is to be expected that a student from an enriched socio­
cultural environment, and with an early start in the English 
language (which is the medium of expression used in science 
textbooks) i woilld probably experience a lesser beading ' 1 "f 
difficulty than one lacking such opportunities.
Furthermore, Ogunniyi (1982) ascertained that most 
science textbooks are only adequate for the top twenty per­
cent of Nigerian science students population. This implies 
that the remaining eighty per cent or so, would have to cope 
with reading materials far above their level of cognitive
UNIVERSITY OF IBADAN LIBRARY 
62
development. One can say, therefore, that there is a mis­
match between the expectations of the authors and those of 
the readership. This same phenomenon was identified for 
science textbooks in Britain (Shgyer and Adey, 1983).
In addition to the earlier cited findings of Guthie 
(1972), Gould ( 1977) ; Carrick (1978) and Baker (1979) had 
also found that science textbooks in use in British schools 
have relatively low readability index. They however found 
out that this applied to students with a wide range of ability. 
Carrick's (1982) assessment of recently published biology 
textbooks in Britain have indicated that the texts have 
achieved a better readability index.
As earlier\   indicated, readabi ility is a highly complex 
concept* This is more so when one realises that many factors 
other than the Written material contribute to the overall 
readability of a given textbook. Gilland (1972) as cited 
by Carrick (1982) observed that readability involves the 
intricacies of language, legibility, motivational interest, 
understanding and reading speed. Etfanec; (1976) and Okpalla 
(1982) contend that readability formulae are difficult to 
apply for books with much technical vocabulary, Uche (1979)
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63
ascertained that although readability is a significant 
factor in comprehension, the authors* style of writing 
ranges from simple to complex depending on the experience 
and background of individual authors0
As shown in these studies, the choice of a readability 
formulae depends on the study and the variables in question,. 
Although some of the readability formulae available are 
cumbersome, this should not imply thei£; total abandonment* 
Their revised versions would continue to provide useful 
information till better formulae are developed* It is not 
likely that a perfect formula would some day emerge* In 
any case, a good formulae for a given context may be>in ffici 
inefficient irt another. Besides, Biology like other science 
subjects is constantly growing* i’he changes ocdtiririg in the 
subject warraKtii the deVelopmeht of hiore sensitive readability 
formulae that could cope adequately with the changes. As 
Carrick (1978) points out, readability studies have to be 
constantly carried out especially on the publication of new 
editions of science textbooks. This will ensure that the 
comprehensibility of the textbooks are constantly monitored. 
The present study is an attempt in this direction.
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64
Summary and Conclusion
In conclusion, it should be pointed out that although a 
considerable number of research studies have looked into the 
readability of textbooks, their findings about the overall 
merit or demerit of the readability indices used vis a vis 
learning are yet to be clearly determined. Besides, there 
are other aspects of communication other than readability 
which may enhance or hinder a reader* s understanding of a 
textual material. These include technical terms, specimens, 
major themes, pictures/diagrams and practical exercises used 
in a given text. Therefore, this study will examine the 
readability of the Various textbooks as well as these other 
areas.
It is hoped that this effort will yield more information 
about seemingly ignored or un-noticed areas that can enhance 
the comprehension or otherwise of biology textbooks and 
indeed science textual materials in general.
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CHAPTER THREE 
RESEARCH METHODOLOGY
This investigation was executed in two phases: a pilot 
study phase and a main study phase* Aspects of the methodo­
logy of research such as the design, instrumentation and 
the general procedure that were common to both phases of 
the study are reported in this chapter* Also reported are 
the specific procedures, results and discussions of the 
pilot study*
Research Design
The design uSed for the pilot and the main study was 
a pretest/post-test dontrol group quasi-ekperimental design* 
The design was a modified version of the Solomon - 3 Experi­
mental Design*
The format of the desigh is as :follows
Experimental Group I i 0.1 k °2 (£,)
Control Group : 03 °4 CC)
Experimental Group II : x 05 (E25
The design is presented in Table 1 below*
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TABLE 1
Design of Experimental Setting
-------------
School and Pre-test Treatment Post-test
Subjects
School 1 SATT Teaching a unit in SATT
biology
Experimental SAT -NUTRITION with selected SAT
Group 1 communicational 
strategies using designed
(fil> SPT notes of lesson SPT
School 2 SATT Placebo treatment is given SATT
Tfee same unit as in E^
Control v/as used BUT without the
Group SAT selected communicational SAT
CC) strategies and notes ofSPT lesson* SPT
School 3 SATT
Experimental Treatment as in E X0 SATGroup 2 None
: (v SPT
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The underlying assumption to this research design is that 
any significant difference between the Experimental Group 1 
(E^) and the Control Group (C) is due to the treatment and 
not as a result of interaction effects of the pre-test.
The validity or otherwise of this assumption is verified 
by the result obtained from Experimental Group II (E^).
In other words, the design controls for pre-test bias 
common to both E1) and C (Ogunniyi, 1986).
Another assumption of the design is the fact that the 
pretest score of is assumed for E^ for comparability 
purposes. Since the subjects chosen were from intact 
daSsee» the design was found suitable for this study.
Variables
The study was in two major parts: the analysis of text­
books, and the experimental study.
Analysis of TdBfeboojcs
This involved the determination of the readability and 
the communicational strategies used in the selected textbooks. 
In this connection, three outcome variables were determined:
1. Readability indices (R.I).
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2. Textbooks analysis (T.B.A.): This was with respect to 
the communicational strategies contained in the textbooks 
involved in the study.
3. communicational strategies survey (C.S.S.): This is with 
respect to recognised preference among producers and 
consumers of communicational strategies in Nigerian biology 
textbooks.
Experimental study
The second dimension of the study is the experimental 
setting. The variables involved are identified below:
A. independent variables: Eight independent variables were 
identified. These include:
1. Leading questions
2. probing questions
3. contextual questions
4. Technical terms defined at first occurrence
5. Local specimens
6. pictures and diagrams (labelled)
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7. inquiry theme
8. challenging practical exercises
All these terms have been defined earlier (page xxvii)
B. Dependent variables; Three dependent variables setting 
were;
1. cognitive achievement
2. Level of development of scientific attitudes
3. Level of acquisition of practical skills 
Sensitivity, internal and External validity
The issue of sensitivity, internal and external validity 
of the study were adequately taken care of. This was with 
respect to the issue of accuracy, generalizability and the ability 
of the research instruments to detect differences present in the 
population of the study.
internal validity specifically deals with the concept of 
accuracy. A strong internal validity can only exist if many of 
the extraneous variables are controlled. campbel and stanley(1963) 
identified the factors that are capable of jeopardising internal 
validity as including*
(a) History; occurrence between the first and second observation 
apart from experimental variables.
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09
70
(b) Maturation: Processes taking place with the subjects 
as a function of time e.g. growing older, getting 
fatigued.
(c) Testing: The effect of the first test on the second 
which may be positive or negative.
(d) Instrumentation: Charges arising from measurement 
instruments or the observers themselves.
Other factors capable of jeopardising internal validity 
are: statistical regression, which can exist when groups 
are selected on the basis of extreme characteristics; biases 
arising from group selection; experimental mortality; and 
selection, depending largely on maturation and similarity.
External validity is concerned about the usefulness of 
a given study, that is the generalizability of the findings. 
Factors that are capable of jeopardising external validity 
include the following;
(a) Reactive or interaction effects of testing e.g. pre­
testing effect - the sensitization to experimental 
conditions.
(b) Reactive effects of experimental arrangements.
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Cc) Multiple treatment effects: that is, the interference
of previous treatment effects with subsequent treatments.
(d) Fail• u• re it o-  describ'e the independent Variables 
explicitly.
Ce) Unrepresentativeness of the target population.
(f) JBswthorrre effect: A situation in which the subjects are 
highly motivated because they are aware of being tested. 
Other factors relate to the poor operationised dependent 
variables; and the interactional effects of extraneous 
factors (Ogunniyi, 1986).
Factors that could jeopardize the internal validity 
were taken care of by a number of steps. Principally, most 
of these factors were annuled by the selection process and 
the use of a control group in the study.
The other factors that could obscure the artifacts of 
instrumentation or treatment were eliminated by isolating 
rival hypotheses through the identification of possible 
covariates, and their subsequent elimination through 
statistical procedures.
The threat of contamination and compensation as a result 
of subjects in different treatment conditions interacting,
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was taken care of by the spread of treatment conditions in 
comparable schools located in different parts of the town* 
This ensured that the subjects in the different treatment 
conditions did not exchange experiencesB
The external validity of the study was also ensured 
by having the regular teachers teach the different groups 
in the study. Within the limitations of the study, it is 
expected that the findings can be extrapolated to settings 
similar to those of the experiment*
Precautions were also taken to ensure the sensitivity 
of the experiment and reduce further the factors that are 
capable of jeopardising the internal and external validity 
alluded to above*
Cox (1958) identified sensitivity as the ability of an 
instrument to detect differences that are present in a 
population* The sensitivity was ensured by a fair selection 
of subjects involved in the study*
The treatment effect was also increased to ensure a 
high within group homogeniety among the experimental 
teachers* The training sessions and demonstration periods 
of the participating teachers also ensured a high between
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groups homogeniety. Constant checks, pre-treatment and 
post-treatment briefings ensured that the teachers operated 
adequately their assigned modes of treatment implementation,. 
Instrumentation
Six research instruments were used in the study for 
data collection,, These were:
1. Readability Index (R.I)„
2* Textbooks Analysis Index (T„B.A.).
3. Comfnunicational Strategies Survey (C0S0S#).
4. Students Achievement Test (S.A.T0)0
50 Students Attitudinal Test (S.A.T.T.).
6<> Students Psychomotor Test (S„P.T.).
I
The first three (R.I*, T0B„A. and C»S„S0) were measures 
for the readability, communicational strategies in the 
textbooks and preference for communicational strategies 
among producers and consumers of biology textbooks.
The other three (S0A0T0, S.A.T8Td and S.P.T.) are the 
dependent variables measures for the experimental study.
The S.R.T. has an accompanied "Pratical Test Assessment 
Inventory", which is an observational guide. Great carre 
was taken to ensure that the final versions of the instruments
UNIVERSITY OF IBADAN LIBRARY 
74
were sufficiently sensitive to defect differences between 
the treatment conditions« The procedures for the developments 
and adaptation of the instruments are discussed in subsequent 
paragraphs.
Readability Index (RqI«) APPENDIX 1
The rea; d/ abil l: i: t.. y- •  i.. n: dices of the t, extbof ok, s .u ,;sed in the 
study was determined usingfflesch* s readability formulae 
(1948), The readability determination was to ascertain 
the difficulty levels of the textbooks and to find out if f. 
they were suitable for the comprehension level of the 
students involved in the study, Flesch*s readability 
formula and its interpretation data relative to Nigerian 
schools were used in interpreting the result obtained in the 
study (Wahome, 1979),
Flesch's readability formula has been used extensively 
by many researchers (Major and Collette, 1961; Marshall,
1962; Wahome, 1979; Jegede, 1982; Okpalla 1982), Although 
Dale-Chall (1948) had indicated that Flesch's formula was 
cumbersome to use, it was found suitable for this study for 
a number of reasons.
First, the formula does not employ any word list.
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Rather, it utilizes measurement of sentence length and 
syllable count. Since it utilizes measurement of sentence 
complexity, and since the count ©frword length and the 
number of syllables per hundred words is an acceptable 
measure of abstraction (Marshall, 1962) it was found appro­
priate for biology textbooks.
The formula was also made available to seven science 
education lecturers and four secondary school biology 
teachers for validation# The characteristics, merits and 
short-comings of the formula were examined# All the 
specialists found the instrument appropriate for biology 
textbooks*
The instrument Was also rated by the Specialists for 
the inter-rater reliability, A reliability coefficient of 
0*96 was obtained using the Spearman-Rank Order correlation 
analysis.
The formula was subsequently applied to a biology 
textbook that would not be used in the study to avoid any 
biases in the main study# The pilot analysis involved, 
’•Modern Biology for Secondary Schools" by Ramalingan et aT 
(1979)o Using the Kuder-Richardson formula 21 (KR21), a
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76
reliability coefficient of 0*96 was obtained. In the 
light of the comments by experts and values of reliability
£  5 i.r '
coefficients obtained, the instrument was subsequently used 
in the main study.
Textbooks Analysis Index (T,B,A.) APPENDIX 3 
The four textbooks used in the study weret 
(i (i) Mackean, D,G, Introduction to Biology,
West African Edition, Heinemann Educational 
Books (Nigeria) Limited, 1982,
(ii) Ewusie, J»Y, Tropical Biology for O’level and 
School Certificate, African Universities Press 
in Association with Harrap* London* 1982,
(iii) Stohe, R«H, and Cozens, A,B. New Biology for
West African Schools, 'Longman Group Limited, 
London, 1982,
(iv) STAN Biology, Addison Wesley, London, 1983,
The T,B,A, was a slightly modified version of the one 
developed by Ogunniyi (1982),
The identified communicational strategies and their 
specific criteria measures examined in this study were as 
followsf
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DAN LIBRARY 
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1. Questioning Styles
(a) Types of Questions:
Ci) Factual
(ii) Rhaotorical 
(iii) Leading 
(iv) Probing
(b) Position of questions:
(i) Introductory
(ii) Contextual 
(iii) Terminal 
(iv) Captional 
2* Technical Terms
(a) Terms defined immediately Used.
(b) Terms earlier defined*
(c) Terms later defined*
(d) Terms Undefined*
3. Specimens
(a) Local specimens
(b) Nonlocal specimens,,
4. Major themes
(a) Evolution
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(b) Ecology
Cc) Economic importance
(d) Inquiry
Ce) History
(f) Knowledge
Cg) Traditional World-view
50 Pictures and Diagrams
(a) Number of pictures
(b) Number of diagrams
Cc) Number of labelled and unlabelled
pictures and diagrams
Cd) Number of colours used for pictures ahd 
diagrams*
6* ftbactlcal Exercises 
(a) Simple
Cb) Specific
(c) General
(d) Challenging
7o Physical Characteristics
(a) Number of colours on the cover*
(b) Number of colours in the text*
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79
7«.
(c) Number of characters (type sizes) used 
in the text.
The instrument was made available to Seven science 
education lecturers, and four secondary school biology 
teachers for validation# They were asked to examine the 
textbooks in terms of the criteria listed above.
The specialists determined the face and content 
validity of the instrument, and fouhd it Suitable for the 
study.
The instrument was also rated by the specialists in 
terms of their suitability. The reliability coefficient 
of 0*98, was obtained using the Speatman**>Rank Order coirbe*- 
latioh analysis.
The instrument was subsequently used to analyse a 
biology textbook that would not be used in the study to 
avoid any biases in the main study.
Using the Kuder-Richardson formula 21 (KR 21) in the 
analysis of "Ramalingan _et al: Modern Biology for Secondary 
Schools" the following reliability coefficients were 
obtained for each of the communicational strategies;
(i) Type of questions, 0,98,
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(ii) Position of questions, 0.
(iii) Technical terms, 0.98.
(iv) Specimens, 0.97.
(v) Major themes, 0.97*
(vi) Pictures and diagrams, 0.
(vii) Practical exercises, 0.96
(viii) Physical characteristics,
In the light of the comments by experts, and values 
of reliability Coefficients obtained, the instrument was 
subsequently used in the main study,,
Communicational Strategies Survey (C.S.S..) APPENDIX 2
The survey determined the preference of communicational 
strategies desirable for biology textbooks as effective 
facilitators of learning* The respondents were the 
Cobsutoers and the producers of biology textbooks* The 50 
respondents (ten in each group) were randomly selected 
from the following;
(i (i) Nigerian biology textbook authors.
(ii) Persons! In Nigerian Publishing Companies.
(iii) Secondary school biology teachers.
(iv) Ministry of education officials involved in 
biology textbooks selection.
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(v) Biology students in secondary schools*
The respondents indicated their choice on a graduated
follows: 
5 ** very essential
V ;
4 tea essential
3 a s sometimes essential
2 s s hardly essential
1 tea not essential*
43 items on the instrument were
eight categories (communicational strategies)* The 
respondents were asked to rate the items as earlier 
indicated* The strategies were questioning styles, tech­
nical terms, specimens, pictures and diagrams, practical 
exercises* map^ themes and physical characteristics*
The instrument WaS made available to seven science 
education lecturers, and four secondary school biology 
teachers for validation* The specialists determined the 
face and content validity of the instrument* In line with 
their comments twelve items were revised before the 
instrument was considered suitable for the study*
The instrument was also rated by the specialists*
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82
Cl ’
A reliability of 0*99 was obtained using the Spearman-Rank 
Order correlation analysis*
The instrument was also administered to 20 respondents 
in a pilot study (four members for each of the five groups 
earlier mentioned)* Using the Kuder-Richardson formula 21 
(KR-2D, a reliability coefficient of 0*98 was obtained*
In the light of the modification done for the valida­
tion process, and in view of the value of the reliability 
coefficient obtained, the instrument was found adequate for :h 
the main Study*
Experimental Setting
The instruments were administered before and after 
treatment* The treatment involved the teaching of a unit of 
biology - NUTRITION * using designed notes of lesson that 
emphasised the eight cotfimunicational strategies involved 
in the study* These wefef
(i) Leading questions.
(ii) Probing questions*
(iii) Contextual questions
(iv) Technical terms defined at first occurrence*
(v) Local specimens.
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(vi) Labelled diagrams and pictures*
(tiiO Inquiry method*
Cviii) Challenging practical exercises*
Notes of Lesson APPENDIX 8
The eight communicational strategies were built into 
the prepared notes of lesson* The treatment lasted for 
six weeks* Although there were inevitable overlaps of 
communicational strategies during teaching, Specific 
time interval were allocated to each strategy to ensure 
an average treatment period for all the Communicational 
strategies*
The notes of lesson was made available to seven science 
education lecturers and four secondary school biology 
teachers for validation* The specialists determined the 
face and content validity* The notes of lesson was 
accordingly modified in line with the experts* comments*
The notes of lesson was also rated by the specialists 
in terms of suitability for the intended purpose* Using 
the Spearman—Rank Order correlation analysis, an inter­
rater reliability coefficient of 0*99 was obtained.
In the light of the modification process for the
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84
validation and a high reliability coefficient obtained, 
the note was used in the main study.
Students Achievement Test (SAT) APPENDIX 6
This is a test of students* cognitive achievement in 
biology* The test items were referenced to the content 
and lesson objectives specified for the treatment* 
Altogether, there were 40 multiple choice questions on the 
instrument*
The instrument was made available to Seven science 
education lecturers and four secondary school biology 
teachers for validation. They examined the face and 
content validity* Their comments led to the restructioning 
of some items, the simiplification of the language, and the 
deletion and/or addition of some items.
The instrument was also rated by the specialists.
An inter-rater reliability coefficient of 0*98 was obtained 
using the Spearman-Rank Order correlation analysis.
The instrument was subsequently administered to 45 Form 
Four students of All Saints Grammar School, Ondo in a pilot 
study. From the responses of the students, the facility 
and discrimination indices of each item was computed.
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The items in the instrument were retained or rejected 
oh the criteria of not including too difficult items as 
well as items that were too easy for the respondents*
Items with discrimination power of more than 0*40 and SO 
facility index of between 40 and 60 percent were retained* 
Using the Kuder-Richardson formula 21 (KR-21) the reliability 
coefficient of 0*92 was obtained.
Students Psychomo_tor Test (SPT)____ APPENDIX 7
This is a modified version of a standardised test of 
skills associated with laboratory and manipulative work.
The skills involved are methodical working, experimental 
techniques, manual dexterity, making and reporting measure­
ments, describing observations, interpreting observed 
data, drawing conclusions, orderliness and observing 
safety regulations during practical sessions. The original 
test was developed and validated by Tamir and Glassman 
(1970) and later modified by Tamir, Nussinovifz and 
Friedler (1982).
The SPT was modified to involve those items related 
to the lesson topics of the study. All the SPT had an 
accompanying S'.udents Psychomotor Assessment Inventory (SPAI),
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The SPAI had a checklist with respect to the behaviour 
exhibited* Each behaviour exhibited was rated on a three 
point scale:
2: faaximum behaviour exhibited*
Is average behaviour exhibited*
0: no behaviour exhibited*
The SPAI was used in assessing students’ psychomotor ability® 
The items in the SPAI are shown in the table below;
TABLE 2
Students Psychomotor Assessment Inventory (SPAI)
Criteria Assessed 2 1 0
1. Sectioning skill (correct pldtte 
of section)*
2* Addition of adequate number of 
iodine drops.
3. Addition of adequate number of 
f<hling*s solution drops*
4* Method of mixture and shaking of 
mixture*
5. Heating techniques.
6* Ease of handling apparatus
7* Accuracy of observation*
8. Drawing skill accuracy.
9* Carrying out exercise to time.
10. Accuracy of recording and reporting 
observation.
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The items used for the SPT included;
(a) Onion bulbs*
(b) Iodine solution,
(c) Fehlings solution I and II (Mixed),
(d) Test tubes.
(e) Handlens.
The SPT and SPAI were validated by seven science 
education lecturers and four secondary school biology 
teachers. Using, Spearman-Rank Order correlation the 
inter—rater reliability coefficient obtained on the SPAI 
was 0,95,
The SPT and SPAI were also administered to 45 form 
four students as in the SAT, Using the Kuder-Richardson 
formula 2i (KR-21), a reliability coefficient of 0*92 
was obtaihed for the SPAI,
Students Atti.tu d—in■—a—l Tes■t■ ■■ (S A—T T" )   A P—P ENDI.X. .. 5— 
The attitudinal test is a modified version of Ogunniyi's 
(1978) inventory on students attitude to biology. It was 
adopted to take care of the various communicational 
strategies involved in the study.
The items in the instrument were generated from; the
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nature of biology, learning, learner characteristics, 
social expectations, teacher's teaching style and the 
learning environment
The respondents reacted to the items in terms of;
Agreement *» 2
Disagreement « 1
The instrument was validated by seven science educa­
tion lecturers and four secondary school biology teachers0
The instrument was also rated by the experts. A 
reliability coefficient of 0.92 was obtained using the 
Spearman-Rank Order correlation analysis.
The SATT was also administered to 45 form four students 
as in the SAT in the pilot study. On the basis of their 
Score* a reliability value of 0*90 was obtained using the 
Kuder-Richardson formula 21 (KR-21)»
General Procedure
Training of Participating Teachers
Experimental group teachers who participated in the 
pilot and main study phases were subjected to a rigorous 
training programme. This ensured that the teachers 
acquired the competence necessary for executing the designed
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notes of lesson. The training exercises ensured that all 
the teachers exhibited minimum within group variance.
They were prepared using the following training programmes. 
Phase I; The investigator familiarised the participating 
teachers with the general set-up of the study. No indica­
tion regarding the hypotheses to be tested was given to 
the teachers. This phase also included a short talk on, 
"Communicational strategies - their use and implication 
for biology teaching".
Phase 2: Five lessons based on the use of the designed
notes of lesson were presented to the experimental teachers. 
Each lesson was followed by a discussion session involving 
the participants.
Phase 3: Each participating teacher was made to have a
micro-teaching session involving the group in the use of the 
training designed notes of lesson. Each presentation 
was discussed.
Phase 4: The teachers in the three groups were trained
in the administration of all the data gathering instruments. 
This phase focussed especially on the training in how 
practical skills could be assessed using the SPT/SPAI. An
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90
S
instruction package providing a general description of the 
experiment, protocols for each condition and mode of pre­
test and post-test administrations in addition to a flow 
chart of the study's procedure were made available to each 
teacher»
Phase 5: At the end of the training exercise, the teachers
in the various groups were assessed for training effect* 
Teachers who performed below form were disallowed from 
further participation in the study* The extra number of 
teachers involved in the study catered for such mortality* 
Collection of Textbooks
The four textbooks involved in the study; Maekean, 
Ewusie, Stone and Cozens and STAN Biology were obtained 
directly from the respective publishers* This ensured that 
the textbooks used for the study were genuine ones rather 
than the pirated copies* This also ensured that the text­
books editions used were the most current editions availa­
ble in Nigeria*
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91
Schematic Representation of the Research Procedure 
PILOT STUDY MAIN STUDY
Validation of instruments “^■Validation
Readability Index (R»T) (Further if necessary)
Communicational strategies 
Survey (C0S0 S0) o
Textbooks Analysis Index (T,BaA;) S-T0
Subjects Selection Test (SaSaT„) R.I.
Students Attitudinal Test (SaAaTaT„) TBA V
Students Achievement lest (S„A0T0) CSS Pre-test
Students Psychomotor Test (SaPaTa) .(SATT, SAT, SPT)
E£p6tife£fital kp ±((E1)
Control Group (C)
A Treatment 'V
Notes of Lesson (a) E^ and Eg as in 
4 designed notes
Inter-rater reliability (b) Placebo for C
1
Pre-test 
(SATT, SAT, SPT)
Post-test 
TreJartment All groupso
Post-test
(SATT, SAT, SPT)
ReliabilitIy Determination * ---
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The Pilot Study
This phase of the investigation was carried out to 
fulfil three main purposes* First, it was an attempt to 
test the viability and workability of the research design* 
This w§s an attempt to isolate the design weaknesses and 
short-comings and apply necessary corrective measures 
before the main study was carried out. Second, it was 
aimed at collecting further data concerning the reliability 
of the instruments with a view to improving their quality 
and sensitivity. The third purpose of the pilot study was 
to identify the administrative and logistic problems that 
were likely to be encountered in the main study.
Sample Selection
A* Teacherst Six regular biology graduate teachers of All 
Saints Grammar School, Ondo, Independence Grammar School, 
Ondo and Ondo Grammar School, Ondo were selected as the 
experimental and control group teachers respectively.
B® Schools; An inspection of the schemes of work for 
form four biology students in and around Ondo revealed 
that eight schools have not taught their students the 
content specified for the treatment in the study. Three
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schools — All Saints Grammar School, Independence Grammar 
School and Ondo Grammar School - all in Ondo town - were 
selected; the first two as the experimental groups and the 
third as the control group,
* • ;
C, Students: All cl ss four students in the selected 
schools were included in the study for the purpose of 
treatment. However, data in respect of students in only 
one arm in each selected school were collected and analysed® 
The arm was selected on a random basis®
D, Textbooks: The textbooks involved in the study;
Mackean, Ewusie, Stone and Cozen were chosen on the basis 
of their wide usage (Balogun, 1978), and STAN Biology was 
selected on its likely popularity in Nigerian secondary 
schools as the sister publication to STAN Integrated Science,
E, Authors: Four biology textbook authors based in Ondo 
State were selected. They are biology graduates who have at 
least a published book in addition to at least 5 years 
teaching or post—qualification experience,
F, Ministry Officials: Four officials of the Ondo State
Ministry of Education responsible for biology textbooks
selection were selected. They are biology graduates who
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93
have performed such functions for at least 5 years.
G„ Publishers: Four publishing house personel were 
selected. They are biology graduates who have been involved 
in biology textbooks preparation for at least 5 years. 
Instrumentation
The readability indices.were estimated by the Readability 
Index (R«I0)o The communicational strategies in the text­
books were analysed using the Textbooks Analysis Index (T0B0A*), 
while the preferences of communicational strategies among 
producers and consumers was estimated by the Communicational 
Strategies Survey (C0S.S.)0
Achievement data were collected using the Students 
Achievement Test (SAT)„ The scientific attitudes of the 
students were measured using the Students Attitudinal Test 
(SATT)o The sixth outcome measure - practical skills was 
assessed by way of the Student Psychomotor Test (SPT) in 
conduction with the Students Practical Assessment Inventory 
C SPAI)o
The responses of the pilot study samples to these 
instruments when administered as pre-tests were further 
analysed to provide further information concerning their
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SB
reliabilities and item characteristics.
The Kuder—Richardson (21) reliability estimates of 
the instruments were as follows; RI = 0*96; T.B.A. = 0o98; 
C.S.S. = 0,99; S.A.T, . 0,98; SATT = 0,90; SPT/SPAI « 0.95.
Procedure
Training of Participating Teachers
The six experimental group teachers were assigned two 
each to Experimental Groups I and II. The other two teachers 
who were given placebo treatment were assigned to the 
control group. These teachers were subjected to a total of 
two weeks training. It was made up of 80 minutes session 
per day. The schedule of training based on the identified 
phases was implemented. The pilot study thus helped to 
ascertain the feasibility of the training programme*,
At the end of the training period, the investigator 
was satisfied with the high degree of homogeniety obtained 
for the teachers. Although only one teacher was finally 
selected from each group for the purpose of the pilot study, 
this training effect convinced the investigator that the 
teachers that would be trained for the purpose of the main
study would also exhibit desirable homogenous characteristics
UNIVERSITY OF IBADAN LIBRARY 
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needed for each treatment condition.
Pre-treatment Activities
Pre—treatment activities were in the following areas: 
Textbooks: This involved the collections and identifies—
tion̂ .of textbooks to be used in the readability determina­
tion and textbooks analysis. The 1982 editions (the most 
current) of the textbooks were used, and STAN 1983 edition. 
The pages were examined to make sure there were no missihg 
pages.
Communications Strategies Survey Respondents: To reduce 
communication and enhance a fast administration of the C,S,S. 
in the pilot study, the investigator carried out a p:. 
preliminary survey of respondents* locations.
Teaching Unit: This involved the visit to some schools in
and abound Ondo town to identify a unit to be taught during
• i i
the treatment phase, NUTRITION was the unit Chosen, because 
it has not been taught in all the schools visited and the 
schemes of work showed that it would not be taught before 
the completion of the main study.
For the treatment period, the unit - NUTRITION was 
broken down into the following lesson topics;
UNIVERSITY OF IBADAN LIBRARY 
1. Food for metabolism,,
20 Holophytic, holozoic and saprophytic nutrition,,
3* Mineral salts for mammals and angiosperms,,
4* Carbohydrates, fats and proteins: their composi­
tion, use and guide to food test®
5« Vitamins: Sourcae* functions and deficiency 
diseases*
60 Feeding methods of animals: herbivo fiB, carhivores, 
omnivores, fil :er-feeders, parasites and 
saprophytes*
7* Digestion and its consequences: Ingestion, 
physical and chemical digestion*
8* Mammalian teeth and ^aws: Tooth structure and 
types of teeth*
9* Herbivores and carnivores teeth and jaws*
10* Mammalian alimentary canal*
11* Absorbtion of food at the villi*
12* Practical exercises on food tests, and experiment 
with digestive enzymes*
13* Gut of herbivores and carnivores.
14* Storage of food.
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15® The liver: Functions and secretions*
16o Diet-- .balanced ‘.diet and the occurrence of 
Kwanshiokor.
Notes of Lesson: These have been designed for the treatment 
period* It was based on the identified teaching unit*
The notes of lesson emphasised the eight communicational 
strategies under consideration* The notes indicated specific 
time allowed for the treatment of a material and the 
specific communicational strategy involved. For the six 
weeks duration assigned for the study, treatment was for 
80 minutes per week*
On the appointed day when the study was expected to 
start, each teacher administered the SAT, SATT ehd SPT/SPAX
as pte-*1t est to the eXperI imehtal grounp and control group C.
i ■
A list of materials and all the materials heeded 
during the treatment phase were collected and checked.
These included! Onion bulbs, iodine solution, fehling*s 
solutions I and II (mixed), razor blades, test-tubes and 
hand lenses.
Only the experimental groups and E2 used the designed 
notes of lesson, while the control group C were taught based
UNIVERSITY OF IBADAN LIBRARY 
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on the teacher^ style ahd method*
Treatment Implementation
Ihe treatment phase were in different categories,,
Each stage is described blow:
■v ■>} ■ f  > -iv.'iC. '
Readability Determination
Fleedh*3 (1948) readability formulae and its interpre­
tation data relative to Nigeriah schools was used (Wahome, 
1979) 4 The readability indices were for all the textbooks 
involved in the study®
Twenty pages were sampled from each of the textbooks 
used in the pilot stlidy. The procedure adopted was, to 
sample every tehth page starting from page one.
F*rom each of the sampled pages, a paragraph with about
i
100 Words were choseh. The following data Were subsequently 
quantified;
(i) Number of words in the sample.
(ii) Number of syllables in the sample.
(iii) Number of sentences in the sample.
(iv) Average sentence length (ASL).
ASL = Number of words in the sample
Number of sentences in the sample
(v) Word length = Number of syllables in 100 words.
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From the data, the Flesch's readability score $RS) fob 
each of the pages is given by;
ReS, « 206.835 0.846 WL - 1*015 ASL.
Where ReS* = Beadability scote; WL *= Word length;
ASL = Average sentence length.
For all the textbooks, the readability score was 
estimated for all the sampled pages. The average readabi­
lity score for each textbook Was subsequently estimated.
The readability scores were then interpreted using 
adapted Wahome's (1979) interpretation of readability data 
relative to Nigerian schools.
lABLE 3
Wahome,t1979) Ihterpbetiation Data (Adapted)
Readability Scores 70-79 60-69 50-59 40-45
Average sentence 
length (ASL) 14 17 21 25
Syllables per 100 
words 139 147 155 167
Description of style Easy Fairly
(4th Year Students) Standard Fairlyeasy difficult
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Communicational Strategies Analysis
The communicational strategies specified for the study 
that were used in all the textbooks were analysed* These 
were in respect of all categories of: questioning styles, 
technical terms, specimens, major themes, pictures and
diagrams, practical exerr cises an' d physical cha- r4 . acteristics.
The same sampling method was used as in the readability 
determination,
Communicational Strategies Survey
The survey was to determine among producers and 
consumers of biology textbooks their preferences of the 
type and nature of communicational strategies they preferred. 
Four members of the groups involved were randomly 
selected for the survey. Altogether, there were twenty 
respondents in the pilot study.
Each of the respondents was given the instrument to 
complete. The respondents in the presence of the investigator 
read through the material for necessary clarifications. On 
the average, each respondent spent 40 minutes to complete
the instrument
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102
Experimental Setting
At the end of the secor•.?. week, the experimental and 
control groups teachers engaged the students in biology 
lessons based on individual notes of iesson.
I i.
In each condition, the teacher started by briefly 
reviewing the previous lesson and then introduced the day*s 
lesson to the whole class. This took an average of 5 minutes® 
The new materials were then introduced* This usually 
lasted for about 70 minutes* Towards the end of the lesson, 
the teachers reviewed the lesson. This lasted about 
5 minutes*
Post-Treatment Stage
This stage only involved the experimental setting.
This stage was executed at the end of the treatment Stage*
The post—test involved the administration of the SAT, SATT 
and SPT/SPAI* These were exactly the same instrument as 
the one used in the pre-test stage. This fact was never 
disclosed to the teachers, nor the students, it was 
exclusively known to the investigator.
Each of the instruments were administered for 60 minutes 
each* The sequence adopted was; Day Is SATT; Day 2s SAT;
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0
and Day 3: SPT/SPAI, This was done in the week immediately 
after the treatment phase*
Conclusion
It is pertinent to observe that the pilot study has 
provided certain useful information such as|
(a) A reasonable degree of confidence in the design 
used in the study*
i . . . (
(b) An improvement in the quality and the sensitivity 
of instruments,
(c) Availability of instructional materials for the 
main study,
(cl) The development of useful experiences and insight 
relative to the rigour involved in carrying out 
an experiment in a field setting.
It was the investigator's hope that the pilot study 
would provide a suitable platform upon which the main 
study would be based.
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3
CHAPTER FOUR 
MAIN STUDY METHODOLOGY 
Sample Selection
The following samples were involved in the main study,,
1, Biology Textbooks: The four biology textbooks involved
in the study were:
(a) Mackean, D,G* Introduction to Biology* West 
African Edition* Heihemann Educational Books 
(Nigeria) Limited, 1982,
(b) Ewusie, J*Y. Tropical Biology for 0*Level and 
School Certificate, African Universities Press 
in Association With Harrap, London, 1982,
(c) Stone, R,H. and Cozens, A,B. New Biology for 
West African Schools, Longman Group Limited,
London, 1982,
(d) STAN Biology, Addison Wesley, London 1983,
The first three were chosen on the basis of their
popularity and wide usage (Balogun, 1978)0 The fourth is 
the latest biology textbook in the market, it was selected 
as earlier stated on the probability of its success judging 
from an earlier effort with respect to STAN Integrated Science,
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0
, ' s‘v
2. Publishing Company Personal: Ten randomly selected
personel in the publishing industry were involved in 
the survey aspect of the study* They are biology 
graduates with at least five years experience in the 
publication and/or marketing of biology textbooks*
They were all based in Oyo State*
3* Ministry of Education Officials: Ten randomly selected 
Ministry of Education officials were involved in the 
C.S.S* They are biology graduates who had been involved 
for at least five years in biology textbooks selection 
for schools in Oyo State.
4« Authors of Biology Textbooks: Also included in the
C.S.S* were ten randomly selected authors who had 
published et least a biology textbook for the Nigeriah 
secondary schools. Co-authors and contributors to 
biology textbooks were included* They were all biology 
graduates with 5 years post-qualification experience 
in the educational enterprise*
5* Biology Teachers: A random selection was made of 19
biology teachers from Oyo State secondary schools.
Ten of them participated in the C0S.S# and nine in the
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experimental setting. They were all biology graduates 
with at least 5 years post-qualification experience.
The selection of the experimental setting teachers 
was based on two conditions.
First, the teachers should be amenable to the vigorous 
training programme required of the experiment. The 
regular teachers fulfilled this condition.
Second, participating teachers must be able to operate 
within the school system for a minimum of fourteen 
weeks. This also made the choice of the regular 
teachers imperative. Although only three teachers 
participated in the experiment, the decision to allow 
additional six was to make ample provision for mortality 
during training as well as during the treatment period.
6. Students: One hundred and fifty-four students were
involved in the study. They were selected from three 
secondary schools in Ibadan. Form four students were 
found desirable because unlike the form three students, 
they had been sufficiently exposed to biology. Also 
they are not under any pressure to prepare for the 
WASC examination as is the case of form five students.
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70 Secondar, y  Schools: Three secondary sch• o,ols in Ibadan-A.
were selected for the main study* The three selected 
schools were;
(i) Cheshire High School, Ibadan: Experimental Group
1 (Ea).
(ii) Jericho High School, Ibadan: Experimental Group
2 (E2)0
Ciii) Bishop Onabanjo High School, Ibadan: Control 
Group (C).
The selection of the schools was based on the following 
criteria;
(i) The schools were approved by the Oyo State Ministry 
of Education to offer science subjects at the 
WASC examination*
(ii) The schools had approved science laboratories as 
determined by WAEC.
(iii) The schools had qualified biology teachers, with at 
least a graduate in biology who had a minimum of 
five years post-alification experience,
(iv) To further ensure comparability of schools, a
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108
"Subject Selection Test" (SST) was administered. Originally, 
twelve schools with a population of 486 students were 
involved. On the basis of their performance, three schools 
with comparable results were selected. This is given below;
TABLE 4
Pre-Treatment Sample Mean Score in Nine Schools
School N X S.D,
"*..1 48 46*13 2.44
2 48 45.96 2.44
3, 48 45.94 2*40
4 48 50*14 3.0
5 48 40.12 2.21
6 48 40.24 2.23
7 48 35.24 2.01
8 48 34.91 1.91
9 48 53.12 3.21
The comparability of the schools was further confirmed 
by the low t—test values, A critical t-test value of 2,01
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109
o ;
was required to establish any significant differences in 
the three schools. In no case did the t-test value reach 
unity in all the pairviisecomparisons. This is given below;
TABLE E
Pre—Treatment Sample Scores Analysis in the 
Three Schools Selected (N = 48
X T-test
School ' X I S.D.ai Difference Value
1 46.13 2.44
vs 0.17 0.40
2 45.96 2.44 (ns)
1 46.13 2.44
vs 0.19 0.40
3 45.94 2.40 (ns)
2 45.96 2.44
vs 0.02 0.06
3 45.94 (ns)2.40
Note; ns = not significant at 0.05, — level.
It should be pointed out that the content of the S.S0T„
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was not in any way related to the content of the instruments 
used in the study*
The SeS.T. (APPENDIX 4) was administered eight weeks 
before the begining of the main study,.
The S0S„T0 was made up of 50 items. The content was 
based on the extent of coverage of designed syllabus for 
form three students in biology for Oyo State secondary 
schools. Originally, it consisted of 60 items. However, 
after the validation process by nine secondary school biology 
teachers, ten items considered unsuitable were eliminated 
leaving 50 items on the test, A preliminary administration 
of the instrument on 48 other students yielded a reliability 
coefficient of 0*97 using the Kuder-Richardson 21,
As Can be seen in Table 5; the three school choseh 
were not significantly different from each other* The 
schools and their students were consequently found suitable 
for the study.
Instrumentation
All the instruments employed for data gathering during 
the pilot study phase were used after appropriate modifica­
tions were made. The coefficient of reliability (KR 21)
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« . .  .
■' ‘ Ji,i . $  1 0■:
obtained for the instruments for the main study sample are;
RI == 0,97; T.B.A. = 0.97; C.S.S. = 0.98; S.A.T. = 
0.97; S.A.t.T. * 0.90; and SPT/SPAI * 0.95.
Procedure
Four weeks before the study began, the nine teachers 
involved in the study were subjected to a training programme 
identical to that of the pilot study. It was relatively 
easier implementing the training programme during this 
phase of the study. During the training session the 
investigator assessed the experimental group teachers for 
training effect. This was complemented with discussions 
on noticed deficiences.
At the end of the training, the experimental and control 
group teachers adjusted their time-table. This was to ensure 
that a lesson lasted 80 minutes and convinient for the 
investigator to be present for at least 50 minutes during 
the lessons.
For the readability determination and textbooks 
analysis, the investigator collected all the textbooks to 
be used for examination. The examination was to ensure 
that the texts were the most current editions (all were
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1982 except STAN Biology which was 1983) available in 
Nigeria* The examination also involved ensuring that the 
texts were genuine ones since textbooks pirated are 
numerous in Nigeria* All the pages of the textbooks were 
also ascertained to ensure there were no missing pages*
After these examinations, the investigator commenced 
with the readability determination of all the textbooks*
This lasted for seven days consecutively*
The textbooks analysis was carried out a week after the 
readability determination of the textbooks* The analysis 
lasted for ten days*
Respondents’ preferences for communicational strategies 
in biology textbooks were sought two weeks after the text­
books analysis* The survey was done in two weeks.
Pre—Treatment Activities
The pre—treatment activities as were carried out in 
the pilot study were also ensured in the main study. This 
was with respect to the textbooks to be used, the survey 
of respondents, the teaching of the units and the notes of 
lesson.
The first 3 days of the experiment was devoted to the
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administration of the SATT, then the SAT and the SPT/SPAI 
on the third day* This pre-test phase was only for £xp:‘ 
Experimental Group I (E^) and Control Group (C).
The investigator also ensured that the Experimental 
Group 1 and 2 (E^ and E^) teachers had their designed notes 
of lesson. The materials for the practical sessions were 
also checked. The teacher for the Control Group (C) was 
also checked to ensure that he has the scheme of work and 
the topics to be taught.
Treatment Implementation
The treatment was implemented as described for the pilot 
study. A rigorous check and monitoring system was employed 
to ensure the reliability of treatment implementation. Three 
teachers previously trained took part in the experiment.
The treatment lasted for six weeks. The Experimental Group 
teachers 1 and 2, (E^ and E^) use the Same treatment while 
the Control Group (C) teacher used his own method. All the 
teachers taught identical content.
Post-Treatment events
At the beginning of the week following the treatment, 
the SATT, SAT and SPT/SPAI were administered to all the
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3
groups as post-test. The teachers involved in the study 
were written letters of appreciation and later visited by the 
investigator* Scheduled visits were also paid to the 
publishing houses, ministry of education and Principals to 
express gratitude for their understanding and co-operation* 
Observations in the Field
There were numerous problems which investigators might 
encounter. Hearney's (1969) schema, modified by Balogun 
(1975) identified the following;
(i) Personals Time, administration and public relations*
(ii) Designs Design features, sample and tests.
(iii) Schools Head, teacher and pupils.
(iv) Materialss Relevance.
In addition to the time and care required for the 
readability determination, textbooks analysis and survey of 
preferences, it is worth mentioning the difficulty involved 
in getting an accurate syllable count. In the end, the 
investigator and four english graduates had to use tape- 
recorded paragraphs of the sampled books to get the accurate 
syllable counts*
Obtaining the necessary co-operation from school heads
V/BS r
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was also a difficult task. With low student-teacher ratio; 
others on maternity leave or leave of absence, many 
principals saw the investigator as an intolerable intruder 
who came to distrupt the school scheme of work. These 
problems had made it difficult to involve as many schools 
as one would have wished in the study.
Analysis of the data
All the data collected for testing the hypotheses were 
analysed with the computer using the appropriate SPSS sub- 
programmes.
The F-test and t-test, were found adequate in determ­
ining the differences that might exist in the samples 
compared.
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CHAPTER FIVE 
RESULTS . ;: f?' r- :
In this chapter, the results have been presented as 
they relate to the hypotheses of interest. In presenting 
the result, the descriptive and inferehtial Statistics ~ * 
associated with the dependent variables have been described. 
Hypothesis 1 (Ho 1)
There is no significant differercein the frequency of 
questioning styles, technical terms, major themes, 
diagrams and pictures, specimens and practical exercises 
used by the four biology textbooks involved in the study.
This hypothesis was tested using the analysis of variance 
and Tukey's post—hoc test.
Questioning Styles
The levels of questioning styles analysed included: 
factual, rheotorical, leading, probing, introductory, 
contextual, terminal and captions!*
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TABLE 6
Frequency and Percentage of Types of Questions Used in 
Four Biology Textbooks
Type
of ST MK EW SC
Questions Freq % Freq % Freq % Freq %
Factual 153 78046 270 79.65 200 85.47 142 89.30
Rheotori-
cal 0 0.00 0 0.00 0 0.00 0 0.00
Leading 14 7.18 36 10.62 14 5.98 7 4.41
Probing 28 14.36 33 9.73 20 8.55 10 6.29
Total No* 
of 195 339 100.oc 234 100.00 159
Questions 100.00 100.00
No of 
Statements 12,530 3,6009£e»fi5 8,895 4,820
Percentage 
of Ques­
tions per 
Statement 1.60 3.53 2.63 3.30
Key: ST = STAN BIOLOGY; MK = MACKEAN; EW = EWUSIE
SC = STONE AND COZENS.
Table 6 represents the frequency and percentage of the 
different types of questions in the four biology textbooks®
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The table reveals that all the textbooks have mostly 
factual questions* The magnitude was in the order of ST = 
153 (78.46%), MK 270 (79.65%), EW 200 (85.47%) and SC 142 
(89.30%). Rheotorical questions were not represented in 
any of the textbooks* Leading and probing questions ranged 
from 4% to 15% which is very low.
TABLE 7
Frequency and Percentage of Questions by Position in Four 
Biology Textbooks
Position ST MK EW SCof
Questions Freq % Freq % Freq % Freq %
Introduc-
tory 0 2 0.59 0 0.00 9 5.66
Contextual 0 0.00 9 2.66 0 0
Terminal 195 100.00 328 96.75 234 100.00 150 94.34
Captional 0 0.00 0 0.00 0 0.00 0 0.00
TOTAL 195 100.00 339 100.00 234 100.00 159 100.00
Key: ST = STAN BIOLOGY: MK = MACKEAN: EW = EWUSIE
SC = STONE AND COZENS.
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Table 7 also represents the frequency and percentage 
of questions in the textbooks with respect to their position 
of occurrence., The table indicate a preponderance of 
terminal questions represented ae ST 195 (1*00%); MK 328 
(96*75%); EW 234 (100,00%); SC 150 (94,34%), Amongst the 
textbooks, contextual questions was present only in Mackean 
9 (2,66%), In all the textbooks, introductory questions - 
were poorly represented, while captional questions were 
not represented at all.
On the whole, Mackean has the highest number of questions.
It contained 339 questions in 9,600 statements which is 
about 3,53%. of questions per statement,
Ewusie has 234 questions ih 8,895 statements represen­
ting 2.63% of questions per statement.
Stone and Cozens has the lowest number of 159 questions 
in 4,820 statements, representing 3.30% questions per statements.
With 195 questions in 12,530 statements, STAN Biology 
has the least percentage of 1.60% per statement.
The summary of the analysis of variance performed on the 
questioning styles scores is presented in Table 8,
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TABLE 8
, . w  " i l l  i t '  t'
Summary of the Analysis of Variance of Introductory, 
Contextual. Terminal4 Factual, Leading and Probing 
Questions (Questioning Styles) in Four Biology Textbooks
Measure Source SS df MS 'F F
(Strategy)
Between 10166.80 3 3388.93
Factual Within 28000.00 36 780.00 4.34*
Total 38166.80 39
Between 4767.50 3 1589.17 7.15*
Leading Within 8050.00 36 222.00
Total 12817.50 39
Between 3027.50 3 1009*17 4*83*
Probing Within 7520.00 36 208.89
Total 10547.50 39
Between 447.50 3 149.17 0.00
Introduc­ Within 0.00 36 0.00
tory
Total 447.50 39
Between 480.00 3 160.00
0 . 0 0
Contextual Within 0.00 36 0.00
Total 480.00 39
Between 3 5733.00 4.50*
Terminal Within 45000.00 36 1250.00 j ./
Total 62202 39
Textbooks = ST (STAN BIOLOGY); MK (MACKEAN); EW = EWUSIE;
SC = STONE AND COZENS ;
Ftable (Critical value) = 4.31;^—Level = 0.001; * = Signifi­
cant scores.
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On the basis of the F-values in Table 8, the following 
decision has been reached concerning Ho^j
The notion that there is no significant difference in 
the number of factual (F3,36 = 4*34, p ̂  0.001) ; leading 
(F3,36 = 7.15, p^OoOOl); probing (F3,36 * 4.83, p ^0.001) 
and terminal (F3,36 = 4.50, p<^0.001) questions can not be 
upheld and the hypothesis is therefore rejected.
However, the assertion that there is no significant 
difference in the number of introductory (F3,36 = 0, p<i&.001) 
and contextual (F3,36 = 0, p<^0.001) questions have been 
upheld, and hence the hypothesis is accepted.
In all these cases a critical F-value of 4031 is 
needed to reject the Null hypothesis.
®he strategies that displayed significant differences 
were further subjected to _a posteriori contrasts.
Application of the Tukey's test indicates that these 
•Honestly significant Differences' lie as in Table 9.
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t a b l e 9
Summary of Tukey' s a posteriori procedure on Introdutory,
Contextual, Terminal, Factual, Leading and Probing 
Questioning Styles in Four Biology Textbooks
Measure
(Strategy) Range of Significant Scores
Factual Mk (270.00))>EW (200.00)>ST (153.00)^SC 4142.00)
Leading MK (36o00)^> ST (14.00) - EW (14.00)^>SC (7.00)
Probing MK (33fc00)̂ >ST (28.00)>EW (20.00)^ SC (10.00)
t:
Introductory No significant differences
Contextual No significant differences
Terminal MK (328.00)^EW (234.00)^ST (195.00)^SC (150.00)
Key: ST = STAN BIOLOGY; MK 4 MACKEAN; EW = EWUSIE 
SC = STONE AND COZENS,
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Factual questions: Mackean Was found to have significantly 
higher number than Ewusie. Ewusie in turn w§S higher than
' J ; V f . ■'
STAN Biology, while STAN Biology had significantly more 
factual questions than Stone and Cozens. As in Table 9, 
the performance is in the order of; MK y  EW ST ̂  SC*
Leading questions? The significant differences were in the 
order of Mackean, followed co-jointly by STAN Biology and 
Ewusie and lastly Stone and Cozens. As in Table 9, the 
performances are in the order of; MK ̂  ST «*» EW SC,
Probing questions: The significant difference in the number 
of probing questions ranged from Mackean, then STAN Biology, 
Ewusie and lastly Stone and Cozens. As indicated in Table 9, 
the performances are in the order of; fil£ VST EW > SC„ 
Terminal Questions: The significant differences ranged 
from Mackeah, then fiwusie, STAN Biology and lastly Stone and 
Cozens, that’s MK > EW > ST SC (Table 9).
Technical Terms
The different levels of technical terms analysed were: 
terms defined at first occurrence; terms defined immediately 
after their occurrence; terms defined later in the text 
and undefined terms.
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TABLE 10
Frequency and Percentage of Technical Terms Used in Four 
Biology Textbooks
Technical ST MK EW SC
Terms Freq % Freq % Freq % Freq %
Defined at 
first
Occurrence 346 91.53 481 89.07 240 86.02 370 84.67
Defined 
immedia£ 
tely after 
occurrence 22 5.82 40 7.41 24 8.15 30 6.87
Defined 
later in 
text 10 2.65 19 3.52 15 5.83 17 3.89
Undefined 0 0.00 0 0.00 0 0.00 20 4.57
Total 378 100.00 540 100.00 279 100.OC 437 100.00
Keys ST = STAN BIOLOGY; MK = MACKEAN; EW = EWUSIE 
SC = STONE AND COZENS.
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Table 10 represents the description of the frequency 
and percentage of technical terms in the textbooks,.
As shown in Table 10, all the textbooks defined most 
of the technical terms at their first occurrence. It was 
found out that there were few technical terms defined 
immediately after occurrence. Technical terms defined 
later in the text were fewer still. Except Stone and
Cozens with a few undefined technical terms, virtually all
-  '  . ;
the textbooks de• fii. ned their term: s*> .
When the defined technical terms in the Sour textbooks 
are considered, Mackean was found to contain the highest 
(540), Stone and Coaelas was next with 417* less 20 undefined 
technical terms) STAN Biology had 378 and Ewusie had the least 
number of 279*
In addition, in Stone and Cozens, it was fouhd that 
there were more undefined technical terms 20 (4*57%) than 
technical terms defined later in the text 17 (3*89%)*
The summary of the analysis of variance performed on 
the technical terms is provided in Table 11.
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TABLE 11
Summary of the Analysis of Variance of Status of Technical 
Terms Used in the Four Biology Textbooks
Measure
(Category) Source SS df MS F
Defined 
at first Between 5403.48
3 1801.16 8.12*
occurrence Within 8000.00 36 222.20
Total 13403.48 39
Defined Between 1960.00 3 653.33
immedia­ 4.58*
tely after Within 5140.00 36 142.78
occurrence Total *7100.00 39
Defined Between 447*50 3 149.17
later 4.41*
Within 1216.50 36 33.79
Total 1664.00 39
Between 2707.50 3 902.50 5.08*
Undefined Within 6400.00 36 177.78
Total 2711.50 39
Textbooks = ST (STAN BIOLOGY); MK (MACKEAN); EW (EWUSIE);
SC ( STONE AND COZENS)»
Ftable (critical value) = 4.31jp<-level = 0,001; 
* =: Significant scores.
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On the basis of the F-values in Table 11, the following 
decision has been reached concerning Ho^:
The hypothesis that there is no significant difference 
in the number of technical terms defined at first occurrence 
(F3, 36 = 8*12, p<^ 0*00i) ; technical terms defined 
immediately after occurrence (F3, 36 = 4*58, p ^  0.001); 
technical terms defined later (F3, 36 *= 4*41, p ̂  0.001) 
and undefined technical terms (F3, 36 * 5*08, p <^0.001) 
has not been upheld by the data available. The critical 
1tfalue needed to reach this decision is 4*31. All the 
calculated F-values are higher than the critical value.
These significant differences were further subjected to 
% ’Eukey'f* _a posteriori contrast test. The test indicates 
that these ‘Honestly Significant Differences’ lie as in 
Table 12.
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TABLE__12
Summary of Tukey's a posteriori procedure on Status of
Technical Terms Used in the Four Biology Textbooks: 
Defined at First Occurrence; Defined immediately after 
Occurrence: Defined later; Undefined
Measure Range of significant scores
(Strategy)
Defined 
at first ST ( 546.00) >MK ( 481.00) >  SC ( 370,00) > EW (240.00)
occurrence
Defined 
immediat­ MK (40.00)^ SC (30.00)>EW (24.00)>ST (22.00)
ely after 
occurrence
Defined
later MK (19.00)>SC (17.00) EW (15,00)y  ST (10.00)
Undefined SC (20,00)y ST (1.00) » MK (1.00) = EW (1.00)
Key: ST = STAN BIOLOGY; MK = MACKEAN; EW = EWUSIE 
SC = STONE AND COZENS.
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Technical terms defined at first occurence! The performances 
were in the order of STAN Biology, then Mackean, Stone and 
Cozen and lastly Ewusie, that’s STy  MK } SC y  EW (Table 
12).
Technical terms defined immediately after occurrences As in
Table 12, the performances were in the order of Mackean, 
then Stone and Cozen, Ewusie and lastly STAN Biology, that's 
MK> SC > EW )> ST„
Technical terms defined later: Mgckean has the highest, 
followed by Stone and Cozens, then Ewusie and lastly STAN 
Biology, that's MK >  SC > EW \ ST (Table 12).
Technical terms undefined: Stone and Cozens had the highest, 
while STAN Biology, Ewusie, Stone and Cozens had equal 
number, though appreciably very low. As in Table 12, the 
performance is of the order; SC ST = MK = EW.
Specimen
The different categories of specimens examined were;
local and nonlocal
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TABLE 13
Frequency and Percentage of Specimen in the Four Biology 
Textbooks
Specimen ST MK EW SC
Freq % Freq % Freq % Freq % !
sI
Local 374 100*00 267 98.52 230 97*87 274 97*51
Nonlocal 0 0*00 4 1*48 5 2.13 7 2*4$
Total 374 100,00 271 100.00 235 100.00 281 100*0
Keys ST = STAN BIOLOGYj MK = MACKEAN5 EW = EWUSIE
SC m STONE AND COZENS*
Table 13 represents the description of the frequency 
and percentage of specimens mentioned in the textbooks*
Table 13 shows that all the textbooks use mostly local 
specimens in their illustrations» STAN Biology which has 
the highest number of local specimens (374), has no non­
local specimen,, Although Stone and Coaens has the next 
highest number of local specimensC274), it also has the
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highest number of non-local specimens (7). BothOM&ckesn 
and Ewusie has 267 and 230 local specimens respectively* 
Also, Mackean and Ewusie had 4 and 5 non-local specimens 
respectively*
The summary of the analysis of variance of the number 
of specimens in the textbooks is shown in Table 14*
TABLE 14
Summary of the Analysis of Variance of Local and Non-Local 
Specimens in the Four Biology Textbooks
Measure
(Strategy) Source SS df MS F
Between 1138*48 3 379.49
\
Local Within 2841.00 36 78.92 4.81*
Total 3979.48 39
between 104.08 3 64.69
Non-Local Within 538.25 36 14.95 4.33*
Total 732.33 39
Textbooks = ST (STAN BIOLOGY): MK (MACKEAN); EW (EWUSIE) 
SC (STONE AND COZENS)*
F table (Critical Value) = 4.31; —Level = 0*001;
• = Significant Scores,
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On the basis of the F-values shown in Table 14, the 
following decision has been reached concerning Ho^;
The ascertion that there is no significant difference
in the number ofI local specimens (F3,36 = 4,81, P <  0.001) 
and non-local specimens (F3,36 =* 4.33, p <C 0.001) has not 
been supported by the findings in this study.
These significant differences were further subjected to 
Tukey's a posteriori contrasts test. The test indicates 
that these ‘Honestly Significant Differences' lie as whown 
in Table 15*
TABLE 15
Summary of Tbkey* s a. Posteriori procedure on Local and Non— 
Local Specimens iin the Four Biology Textbooks ' ” ~
Measute
(Strategy) feange of Significant Scores
Local ST ( 374o00)> SC (274.00)>MK ( 267.00)>EW( 230.00)
Non-Local SC (7.00) > E W  (5.00))>MK (4.00)>ST (0.90)
Key: ST = STAN BIOLOGY; MK = MACKEAN; EW = EWUSIE; 
SC = STONE AND COZENS.
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Local Specimens: STAN Biology was found to contain r' 
significantly the highest number of local specimens followed 
by Stone and Cozens, then Mackean and lastly Ewusie, that 
is ST >  SC V, MK >  EW (Table 15).
Non-Local Specimens: Stone and Cozens had significantly 
more non-local specimens followed by Ewusie, then Mackean 
and lastly STAN Biology, that’s SC >  EW V  MK ̂  ST 
(Table 15).
Major Themes
The various levels of major themes examined were; 
evolution, ecology, economic importance, inquiry method, 
history, knowledge, world-view.
These themes were selected by the investigator baSed 
ori their frequency of occurrence in all the biology textbooks 
ekgmined. their selection was also based on the expressed 
opinion of classroom teachers and science Educators duting 
the validation process* They represent the most prominent 
themes in Nigerian secondary schools biology textbookdl
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TABLE 16
Frequency and Percentage of Major Themes in the Four 
Biology Textbooks
Major ST MK EW SC
Themes Freq % Freq % Freq % Frecl %
Evolution 36 14.00 20 12.90 25 12.14 23 11.98
Ecology 36 14.00 23 14.84 24 11.65 22 11.46
Economic
importance 20 7*78 23 14.84 331 15.05 28 14.58
Inquiry 86 33.46 20 12.90 54 26.21 47 24.48
History 24 9.34 30 19.36 23 11.17 24 12.50
Knowldege 35 13.64 39 25.16 49 23.78 48 25.00
World­
view 2b 7.78 0 OtrOO 0 0 .0 0 0 0*00
TOTAL 25*7 100.00 155 100.00 206 ioo.oo 192 100.00
Key: ST = STAN BIOLOGY; MK = MACKEAN; EW = EWUSIE; SC = STONE 
AND COZENS.
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Table 16 represents the description of the frequency 
and percentage of major themes in the textbooks. As shown 
in the taj^le, all the textbooks haVe the major themes 
well represented in them,, With respect to the evolutionary 
theme, STAN Biology < gad the highest value of 36, while Ewusie 
had 25 and Stone and Cozens had 23. Mackean had the least 
value of 20.
For the ecological theme, STAN Biology had the highest 
value of 36« The other textbooks have comparable values 
of Ewusie 24, Mackean 23 and Stone and Cozens 22,
On economic importance, Ewusie had the highest 
value of 31, then Stone and Cozens 28* Mackean 23 and STAN 
Biology had the least value of 20o
With regatd to inquiry method* STAN Biology had the 
highest value of 86, Ewusie, Stone and Cozens and Mackean 
have 54, 47 and 20 respectively.
For historical theme, Mackean had the highest value 
of 30, STAN Biology and Stone and Cozens had 24 each, 
while Ewusie had 23.
For the knowledge theme, Ewusie had the highest value 
of 49, followed by Stone and Cozens 48, Mackean had 39
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and STAN Biology 35«
Considered on the basis of the most occurring themes in 
each textbook, a clear picture is painted.
In STAN Biology, the range of occurrence is, inquiry
33.46%, evolution 14%, ecology 14%, knowledge 13.64%, history
9.34%, world-view' (  7-,V '7A  8% and economic• importance 7.78%.
The range in Mackean is, knowledge 25.16%, history 19.36%, 
ecology 14.84, economic importance 14.84, evolution 12.90%, 
inquiry 12.90% and world-view 0.00%.
Ewusie has the representation as, inquiry 26.21%, know­
ledge 23.78%, economic importance 15^05%, evolution 12014%, 
ecology 11.65%, history 11.17% and world-view 0.00%.
For Stone and Cozens, the range is, knowledge 25o00%, 
ihquiry 24.48%, economic importance 14.58%, history 12.50%, 
evolution 11098%, ecology 11.46%, and world-view 0.00%.
It is significant to emphasize that traditional world­
view was represented as a theme only in STAN Biology0
The summary of the analysis of variance performed on 
the major themes represented in the textbooks is described 
in Table 17.
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TABLE 11
Summary of the Analysis of Variance of Major themes 
(Evolution; Ecology; Economic Importance; Inquiry; 
'History; Knowledge and tflTld—view in the'four Textbooks
Measure
(Strategy) Source SS-
’ df MS. F’:y.
Between 1460.00 3 4 8 6 . 6 9 ?
Evolution Within 3180.00 36 88.33 8 8 . 3 3 5.51*
Total 4640.00 39
Between 1274.81 3 424.94
Ecology Within 3116.60 36 86.57 4.91*
Total 4390.41 39
Economic Between 730b00 3 243.33
Importance Withih 2015.00 36 55.97 4.34*
Total 2745.00 39
Between 2211.67 3 737.23
Inquiry Within 5220.00 36 145.00 5.08*
Total 7431.67 39
Between 307.50 3 102.50
History Within 845.22 36 23.48 4.36*
Total 1152.72 39
Between 1407.50 3 469.17
Knowledge Within 3282.50 36 91.18 5*15*
Total 4690.00 39
Between 2707.50 3 902.50
Worldview Within O.Of 36 0.00
Total 2707,50 39
TEXTBOOKS = ST (STAN BIOLOGY): MK(MACKEAN)• EW(EWUSIE); SC 
(STONE AND COZENS)* Ftable (CRITICAL VALUE) = 4.31; <X. -level =
0.001; * = Significant Scores.
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On the basis of the F-values in Table 17, the following 
decision has been reached concerning Hô _;
The notion that there is no significant differences 
in the number of evolutionary themes (F3,36 = 5051, p<^0*001) 
ecological themes (F3,36 « 4*91, p 0*001); economic 
importance themes (F3,36 = 4*34, P <  0*001); inquiry themes 
(F3,36 = 5*08, p*^ 0*001); historical themes (F3,36 = 4*36, 
p •̂ ’0*001) and knowledge themes (F3,36 = 5.15, p 0*001)^ 
as contained in the textbooks has not been Upheld with the 
data presented in Table 17.
The notion that there is no significant difference in 
the number of traditional world-view themes is, however, 
upheld (F3£$6 » 0*00, p ^  0*00l), since the computed 
value is less than the critical fVvalue of 4*31*
The significant differences were subjected to Tukey*s 
a Posteriori contrasts test* The application of this test 
indicates that these 'Honestly Significant Differences' 
are in the order shown in Table 18*
V"‘ th rvjr Y - v-. s‘.i V \ n 0 ,»r 0") )
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TABLE 18
Summary of Tukey* s aoposteriori Procedure on Major Themes;
Evolution, Ecology, Economic, Inquiry, History, Knowledge, 
World-view in ^he Four Biology Textbooks
Measure
(Strategy) Range of Significant Scores
Evolution ST(36.00)> EW(25.00)> SC(23.00)>MK(20.00)
Ecology ST(36„00)> EW(24.00)> MK(23.20) )> SC( 22.00)
Economic
Importance SW(31«00)> SC(28.00)> MK(23,00)> ST(20o00)
Inquiry ST(86.00)> EW(54.00)^ SC(46.70)> M K ( 20.00)
History MK(30.00)^ ST(24.00) - SC(24.00)^ EWt23.00)
Knowledge SW(49.00)>SC(48.00y> MK( 39.00)^ ST( 35.00)
Worldview No Significant difference In Scores.
Key: ST = STAN BIOLOGY; MK = MACKEAN; EW = EWUSIE; SC =
STONE AND COZENS.
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EvoX ltionary Themes| STAN Biology was found to significantly 
contain more evolutionary themes than Ewusie# The latter 
in f4c u- En contains more themes than Stone and Co.ze•-n«« Mackean
seems to contain the least occurrence of evolutionary themes# 
As in Table 18, the performances are in the order of;
ST >  EW >  SC >  MK,
Ecological Themes: The performances ranges from STAN Biology 
(highest), then Ewusie, Mackean and lastly Stone and 
Cozens that'* S T > E W > M K >  SC„
Economic Importance: The significant differences vary from 
Ewusie having the highest, then Stone and Cozens, Mackean 
arid lastly STAN Biology, that’s EW >  SC > MK >  ST#
Inquiry Themes; The significant differences vary from 
STAN Biology having the highest frequency, then Ewusie,
Stone and Cozens and lastly Mackean, that’s 
ST >  EW >  SC >  MK#
Historical Themes: Mackean was found to significantly
contain the highest number, followed by STAN Biology and 
Stone and Cozens with equal number, while Ewusie had the 
least number, that's MK ̂  S T SC ̂  EW#
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Knowledge: The significant differences vary from Ewusie
having the highest frequency, then Stone and Cozens, Mackean 
and lastly STAN Biology, that’s E W S C  ̂  MKj> STe 
Pictures and Diagrams
Another aspect of textbooks quality examined in this 
study include; labelled and unlabelled pictures, labelled 
and unlabelled diagrams0
TABLE 19
Frequency and Percentage of Pictures in the Four. Biology 
Textbooks
SC = STONE AND COZEN So
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TABLE 20
Frequency and Percentage of Diagrams in the Four Biology 
T extbook s __ _  “ sc
Diagrams Freq % Freq % Freq % Freq %
Labelled 451 75.17 488 72*511 275 64.55 434 62.63
Unlabelled 149 24£833 185 27.49 151 35.45 259 37.37
Total 500 673 100.00 426 693 100.00
Percentage
t’eir 300.00 336*50 213 .0 0 346.50
Sampled
Pages
Key; ST = STAN BIOLOGY; MK = MACKEANj EW = EWUSIE; 
SC = STONE AND COZENS*
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Tables 19 and 20 represent the description of the
frequency and percentage of pictures and diagrams in the
textbook. s.
An examination of Table 19 on pictures shows that all 
the textbooks are guilty of a preponderance of unlabelled 
pictures. On the whole, Stone and Cozens had the highest 
number of pictures (168), follow&d by STAN Biology (159), 
Mackean (87) and lastly Ewusie (47),
It was also observed that all the textbooks contained 
more diagrams than pictures (Table 20)• Stone and Cozones 
had 693 diagrams; Mackean, 673; STAN Biology, 600 and 
Ewusie, 426,
STAN Biology had the' highest humber of unl&bslled pictures' 
(159), next was Stone and Cozens (149), Mackean (53) and 
Ewusie (46)* /
On unlabelled diagrams, Stone and Cozens had the highest 
(259), Mackean (185), Ewusie (151) and STAN Biology (149),
The summary of the analysis of variance performed on 
the diagrams and pictures contained in the textbooks are as 
shown in Table 210
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TABLE 21
Summary of the Analysis of Variance of Diagrams and Pictures 
in the Four Biology Textbooks
Measure
(Category) Source SS df MS F
Labelled Between 2652,27 3 884.09
diagrams Within 5282.25 36 146.73 6.03*
Total 7934.52 39
Unlabelled Between 7858.10 3 2619.36
diagrams 4.69*Within 20125.25 36 559,03
Total 27983.25 39
_ - „ 2615.3-
Labelled Between^' 762.75 3 254.25 4.53*
Pictures Within 2019.28 36 56.09
Total 2782.03 39
Unlabelled Between 1099.48 3 366.49
4.38*
Pictures Within 3006.00 36 83.50
Total 4105.48 39
TEXTBOOKS ST <= (STAN BIOLOGY • MK(MACKEAN); EW (EWUSIE);
SC (STONE AND COZENS),
Ftable (Critical value) = 4.31;o^ —level = 0.001^ 
* = Significant Scores,,
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On the basis of the F-values shown in Table 21, the 
following decision has been reached concerning Ho^j
The notion that there is no significant difference 
in the number of labelled diagrams (F3,36 = 6o03, p 0o001) 
Unlabelled diagrams (F3,36 = 4.69, p ^ 0.001); Labelled 
pictures (F3,36 = 4.53, p.<̂  0.001); Unlabelled pictures
(F3,36 = 4*38, p ^  0.001) contained in the textbooks can 
not be upheld.
These significant differences were further subjected 
to Tukey* s _a posteriori contrast test (Table 22). The test 
indicates that these 'Honestly Significant Differences' lie 
as shown in Table 22.
As shown in the table, when labelled diagrams and 
pictures are considered, Mackean performed significantly 
better than the other textbooks. Conversely, while Ewusie 
performed lower than the others in labelled diagrams,
Ewusie and STAN Biology had the poorest representations on 
labelled pictures.
The various performances are as follows:
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TABLE 22
Summary of Tukey’s a, posteriori procedure on Diagrams and 
Pictures in the Four Biology Textbooks
Measure
(Strategy) Range of Significant Scores
Labelled MK( 488*00) >  ST( 451*00/ >  SCU34.0Q) >  EW( 275*10)
diagrams
Dniabelled
SC( 259*00) >  MK(185*00)> EW( lSl.dO»>~
diagrams
Labelled MK( 34*00) >  SC( 19.00) > EW( 1.00) «= ST(l.OO)
Pictures
Unlabelled
ST( 159.00) >SC(149.0Q^J>MK( 53*00) EW(46.00)
pictures
Key: ST » STAN BIOLOGY 5 MK » MACKEAN , EW = EWUSIE
SC = STONE AND COZENS
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Labelled diagrams; The significant performances range 
from Mackean having the highest, then STAN Biology, Stone 
and Cozens and Ewusie having the least, fcftgj* £s in the 
order of, M K >  ST > SC >  EW,
Unlabelled diagrams: The significant performances range 
from Stone and Cozens having the highest, then Mackean, 
Ewusie and STAN Biology having the least* The performances 
are in the order, SC MK ,> EW „> ST,
Labelled pictures; Mackean was found to contain signifi­
cantly the highest number. The next in rank is Stone and 
cozens, followed by Ewusie and STAN Biology with equal 
number. The performances are in the order, MK SC > EW 
ST,
Unlabelled pictures: STAN Biology has the highest number, 
followed by S^one and Cozens, Mackean and lastly Ewusie, 
that's S T >  SC >  MK >  EW,
Practical Exercises
The different levels of practical exercises examined 
were; simple, specific, general and challenging.
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TABLE 23
Frequency and Percentage of Practical Exercises in the 
Four Biology Textbooks
Practical ST MK EW SC
Exercises Freq % Freq % F req % F req %
Simple 30 22.06 15 18.29 65 46.10 70 31.39
Specific 28 20539 7 8.54 26 18.44 30 22.42
General 8 5.88 5 6.10 9 6.38 13 5.83
Challenging 10 51.47 55 67.07 41 29*08 90 40.36
Total 136 100.00 82 100.00 141 100.00 223
Key: ST n STAN BIOLOGY; MK = MACKESN; EW = EWUSIE
SC * STONE AND COZENS
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Table 23 represents the description in terms of the 
frequency and percentage of practical exercises in the 
textbookSo As indicated in the table, the textbooks have 
more of challenging exercises and very little of general 
exerciseso Simple and specific exercises were averagely 
represented,,
On challenging exercises, Stone and Cozens had 90, 
which was the highest, followed by STAN Biology (70), then 
Mackean (55) and lastly Ewusie (41)o
On simple exercises, Stone and Cozens had 70, then 
comes Ewusie (65), STAN Biology with 30 and lastly Mackean 
with only 15.
On specific exercises, Stone and Cozens had 50, STAN 
Biology 28, Ewusie 26 and lastly Mackean with 7.
On general exercises, all the textbooks had poor 
representation. Stone and Cozens had 13, Ewusie 9, STAN 
Biology 8 and Mackean 5.
The summary of the analysis of variance performed on the 
practical exercises in the textbooks is provided in Table 24#
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TABLE 24
Summary of the Analysis of Variance of Practical Exercises
in the Four Sioloav Textbooks
Measure
(Strategy) Source SS df MS F
Between 2150,00 3 716.66 r,
Simple Within 5112,20 36 142.01 5.05*
Total 7262.20 39
, i BetWekh 9287.50 3 3095.83
Specific Within 25282.20 36 702.28 4.41*
Total 34569.70 39
o , 1 Between 327/50 3 109.17
General Within 852,30 36 23.68 4.61*
Total 1179.80 39
Between 1322.00 3 440.66
Challenging Within 3285.20 36 91.26 4.83*
Total 4607.20 39
Textbooks = ST (STAN BIOLOGY); MK (MACKEAN); EW (EWUSIE);
SC (STONE AND COZENS).
Ftable (Critical Value) = 4,31; X  -Level = 0,001; 
* = Significant Scores,
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On the basis of the F—values the following decision 
ftas been reached concerning Ho^;
The notion that there is no significant differences in 
the number of simple exercises (F3t36 = 5.05, p v 0,001) ; 
specific exercises (F3,36 = 4,14, p < 0,001); general 
exercises (F3,36 = 4,61, p 0,001) and challenging
exercises (F3,36 = 4,83, p 0,001) contained in the text­
books can not be upheld.
Consequently, with respect to the varying categories of 
practical exercises in the four textbooks, the assertion that 
there are no significant differences in their number is
I
rejected.
The hypothesis Was rejected because a critical value 
of 4,31 is all that is needed to reject the hypothesis.
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TABLE 25
Summary of Tukey’s a posteriori Procedure on Practical 
Exercises in the Four Biology Textbooks
Measure
(Strategy) Range of Significant Scores
Simple SC (70.00)>EW (65.00)> ST (30.00)> MK(15.00)
Specific SC(50.0d)/> ST(28.00) > EW (26.00) >  MK (7.00)
General SC (13.00) >EW(9.00)'> ST (8.00)>MK (5.00)
Challenging SC(9 0 . 0 0 ) ST(70„00)> MK(55.00)^ EW(41.00)
Key! ST = STAN BIOLOGY; MK = MACKEAN; EW = EWUSIE 
SC = STONE AND COZENS„
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These significant differences were further subjected 
to Tukey*s _a posteriori contrasts test (Table 25)• The 
test indicates that these ‘Honestly Significant Differences* 
lie as in Table 25*
Simple exercises: The significant performances ranging 
from the highest to the lowest are; Stone and Cozens, then 
Ewusie, STAN Biology and Mackean, that's SC > EW )> ST MK« 
Specific exercises: The significant performances starting
from the highest to the lowest are; Stone and Cozens, Stan 
Biology, Ewusie and Mackean, that's SC ^ STĵ  EW ̂  MK„
General exercises: The significant performances starting 
from the highest to the lowest are; Stone and Cozens,
Ewusie, STAN Biology and lastly Mackean, that's SC^ EW)>
ST̂ > MK.
Challenging exercises: The significant performances
commencing from the highest to the lowest are; Stone and
Cozens, then STAN Biology, Mackean and lastly Ewusie, that's
SC> ST > MK> EWe
Physical Characteristics 
"
The different types of physical characteristics of the 
textbooks examined in this study were; cover colours, text 
colours and a number of characters in a text*
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TABLE 26
Frequency and Percentage of Physical Characteristics in 
the Four Biology Textbooks
Physical ST MK EW SC
Character­
istics Freq % Freq % Freq %
Freq %
Cover
Colours 7 21*88 5 29.41 4 30.77 4 23.53
Text
Colours 15 46.88 2 11.76 2 15.39 2 11.77
Number
of
Characters 10 31.24 10 58.83 7 53.84 11 64.70
Total 32 100.00 17 lo o.00 13 100.00 17 100.00
Key: ST = STAN BIOLOGY; MK = MACKEAN; EW = EWUSIE;,
SC « STONE AND COZENS
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Table 26 represents the description of the frequency
and percentage of the textbooks physical characteristics.
It was found out that the number of colours on the cover of 
the textbooks were comparable. STAN Biology had 7, Mackean 
5, while Ewusie and Stone and Cozens had 4 each.
Within the text, there were 15 colours in STAN Biology,
while tHe other three had 2e ach. The type of characters
used in all the textbooks were also comparable. Stone 
and Cozens had 11, Mackean 10, STAN Biology 10 and Ewusie 7.
wken the typerof char&dters in the textbooks Are
■ I V ■ •
considered, Stone and Cozehs hadt he highest (11). Next
were STAN B7iology and Mackean with 10 each, while Ewusie had 
onl^ 7 characters.
Wheh the physical characteristics are Viewed as a unit, 
STAN Biology had the highest (32), Mackean, Stone and Cozens 
had 17 each, while Ewusie had the least number of 13.
The summary of the analysis of variance performed on the 
physical characteristics of the textbooks is presented in 
table 27.
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TABLE 27
Summary of the Analysis of Variance of Physical 
Characteristics in the Four Biology Textbooks
Measure
(Strategy) Source 38 df MS F
Cover
Colours Between 60*00
3 20i00
Within 150.25 36 4*17 4*80*
9 Total 210.25 39
Text / Between 12*67.50 3 422J50
Colours Within 3285.20 36 91*26 4*6$*
Total 4&52.70 39
Number
of Between $o.ob 3 30.00Characters Within 240*52 36 6.68 4.49*
Total 330.52 39
TEXTBOOKS = ST (STAN BIOLOGY) ; MK (MACKEAN); EW (EWUSIE);
SC (STONE AND COZENS)
Ftable (critical value) = 4.32; o£-Level = 0*001; * = 
* * Significant Scores*
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On the basis of the F-values shown in Table 27, the 
following decision has been reached concerning Ho^;
The notion that there are no significant differences 
in the number of cover colours (F3,36 = 4.80, p<J3.00l), 
text colours (F3,36 = 4*63, p \ 0.001); number of characters 
in the text (F3,36 = 4.49, p<^ 0.001) contained in the text­
books can not be upheld.
These significant differences were further subjected 
to TukeVts a posteriori contrasts test (Table 28. The 
test indicates that these ‘Honestly Significant Differences* 
lie as in Table 28.
The table shows that in terms of colours used in the
textbook, s^ S- TANi Biology had significantly higher number of 
colours, while EWUSifê  Stohe and tokens had the least 
number of colours.
However, on the number of characters used in the 
textbooks, Stone and Cozens had the highest, while Ewusie 
had the lowest.
The picture for each of this strategy is described as
in Table 28.
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TABLE 28
Summary of Tukey* s .a posteriori procedure on Physical 
Characteristics in the Four Biology Textbooks
Measure
(Strategy) Range of Significant Scores
Cover
Colours ST(7.00)j> Mk (5«00) EW(4o00) SCC4.00)
text
Colours ST(15.00)> MK(2.00) = EW(2.00) l* SC(2iOO)
N lumber 
of SC(lla00)> MK(10*00) ■ ST(10.00)> EWC7.00)
Characters
Key: ST = STAN BIOLOGY; MK = MACKEAN; EW = EWUSIE
SC = STONE AND COZENS
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Cover Colours? STAN Biology was found to contain signifi­
cantly higher niimber than Mackean. Then, followed was 
Ewusie, Stone and Cozens with equal number, that's 
ST> MK^> Ew = SC„
Text Colorrss The colours in STAN Biology was significantly 
higher than Mackean. Next was Ewusie and Stone and Cozens 
with equal number of colours that's ST MK = EW = SCe 
Number of Characters; The performances of the textbooks 
were in the order of MackeSn and STAN Biology with equal 
number of characters,, they however have lower number than 
Stone and Cozens, while Ewbsie had the least, that's 
S C > M K >  «= ST \ EW0
i
Communicational Strategies Survey
In order to demonstrate the relationship between data 
obtained in this study and actual field experiences of 
consumers and producers of biology textbooks, a survey of 
preferred communicational strategies was conducted,, 
Bespondents in the survey included teachers, students, 
authors, publishers and ministry officials.
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TABLE 29
Mean. Standard Deviation of Respondents in the Communica- 
tional Strategies Survey
Strategy Group Mean StandardDeviation
AT 39.00 0.00
Question- 0.68
ing Styles 37.30MPOB 37.30 0.68
T 38.80 0.42
S 37.30 0.68
PABT 15.70 0.48Technical MO 15.80 1.69terms T 15.90 1.6616.00 0.67
S 16.20 1.93
AT 11.70 0.48
PB 0.32
Specimen MO
14.10
14.10 0.32TS 11.50 0.7114.10 0.32
AT 48,00 0.00
Pictures PB
MO 49.90 0.32and 49.90 0.32
Diagrams T 48.20 0.63
S 49.90 0.32
AT 16.30 0.48
Practical PB
Exercises 17.70 0.68MO
T 17.30 0.95
S 16.30 0.4817.70 0.68
AT 35.00
Major 0.00
Themes PBMO 29.00 0.00
T 29.20 0.42
S 35.00 e-.oo29.00 0.00
AT
Physical 29.70PB 0.48
MO 31.80Character- 1.69
istics T 31.60 1.84
S 29.80 0.4231.80 1.69
Keys AT = Authors; PB = Publishers; MO = Ministry officials; 
T = Teachers, S = Students.
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Table 29 represents the mean scores and standard 
deviations of the various group responses to the survey*
An examination of the table reveals the following with 
respect to preferences for communicational strategies used 
in biology textbooks:
With respect to questioning styles, the highest mean 
score of 39 was obtained for authors,, This was followed 
by the teachers (38*80),thao publishers, ' ministry 
officials and students with equal mean scores (37*30)*
On technical terms, the highest mean score 16*20 was 
obtained for students followed by teachers (16*00), 
ministry officials (15*90), publishers (15*80) and lastly 
authors (15*70)*
With regard to specimens, the publishers, ministry 
officials and students had equal mean scores (l4**lo), 
ghesj the authors (11*70) and lastly the teachers (11*50)* 
On pictures and diagrams, the publishers, ministry 
officials and the students again have equal mean scores 
(49*90)* i fhey were closely followed by teachers (48*20) 
and then authors (48*00).
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With r»egard to practical exercises, the highest mean
scores were obtained among the ministry officials and the 
students (17.70; each). They were closely followed by 
the authors (16.30) and the teachers also with 16.30.
On major themes, the highest mean score were obtained 
among the authors and the teachers each scoring a mean 
of 35.00. The ministry officials had mean of 29.20, while 
the publishers and students scored a mean of 29.00 each.
On physical characteristics, the highest mean score was 
obtained by the publishers and students with 31.80 each. 
This is followed by the ministry officals (31.60), then 
the teachers (29.80) and lastly the authors (29.70).
The summary of the analysis of Variance performed 
on the responses obtained in the survey is shown on Table 
30.
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TABLE 30
Summary of the Analysis of Variance on Preferences of
Authors,Publishers.Ministry Officials. Teachers and 
Students Relative to Communicational Strategies in 
Biology Textbooks
Measure
(Strategy) Source SS df MS F
Qusetsytliesoning Between 30*94 4 7*73Within 80.25 45 1.78 4.34*
Total 111.19 49
Technical
terms Between 41.48 4 10.37Within 143ib0 45 3*18 3.26
Total 184*48 49
Between 75*20 4 18*80
Specimens Within 195*52 45 4.34 4.33*
Total 270.72 49
Pictures BetWeeh 39*06 4 9*71
and
Diagrams Within 112.22 45 2.49 3.92*Total 151.28 49
Practical
Exercises Between 20.31 4 5.08Within 52.21 45 1.16 4.38*
Total 72.52 49
Major WBietthwienen 10422..4267 4 10.57Total 45144.73 2.2849 •.«4«64*Themes
Physical
Character- Between 47.52 4 11.88
istics WTiottahlin 110585..2757 4459 2.41 4.93*
Ftable (Critical value) = 3.83; -Level = 0.001;
• <= Significant Scores.
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On the basis of the F—values the following decision 
has been reached:
The hotion that there are no significant differences 
among the groups with respect to their preferences for 
questioning styles (F4,45 * 4*34, p 0*001) ; specimens 
(F4,45 «* 4*33, p ^ 0*001); pictures and diagrams (F4,45 « 
3*92} p ̂  0*001); practical exercises (F4,45 = 4.38, 
p 0*001) ; major themes (4,45 = 4*64, p <^©,001); physical 
characteristics (F4,45 = 4*93, p -^0*001) has not been 
upheld by the data as presented in Table 3©.
However on technical terms, the group exhibited no 
significant differences (F4,45 = 3*26 p ^ 0,001)*
The significant differences obtained were further 
subjected to Ttikey^s a posteriori contrasts test (Table 3D* 
The test indicates that these *Honestly Significant 
Difference lie as in Table 31*
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TABLE 31
Summary of Tukev* s a postoriorl Procedure on Respondents 
Scores in the Communicational Strategies Survey
Measure
(Strategy) Range of Significant Responses
Question-u * w • %
iftg styles AT(39.00)>T(38.80)>S(37o30)=Mo(37o30) = PB(37.30)
Technical
terms No Significant Differences
S'-' i ' •! 1) - . 1 w. j.r:) - 1.1 7' ) 
Specimens 14.10) =MO (14 . IP) =P B (14* 10 )>AT ( llc 70 )>T.( 11. 50)
Pictures
and
Diagrams S(49«90)=M0(49«90)=PB(49o9q)T-(48.20)>AT(48.00)
Practical
Exercises S( 17.70^=PB(17o70)>M0(17o30)^T( 16®30) =AT(16o30)
Major
Themes T(35.00)=AT(35.00)>M0(29®20)>S(29o00)=PB(29,00)
CPhhyasriaccatler S( 31.80)=PB( 31«80)>MO( 31.60)).T( 29.80)>AT( 29.70)
ristics
Key: AT = Authors; PB ** Publishers; HO = Ministry officials; 
T «= Teachers; S = Students®
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Questioning Styles: The significant responses beginning 
from the highest to the lowest are: authors, teachers, 
followed by students, ministry officials and publishers 
with equal values, that's AT̂ > T S = MO = PB„
Specimen: Again students, officials and publishers had the 
s§me value,, Their value were significantly higher than that 
of authorso The authors responses were in turn significantly 
higher than the teachers, that's S = MO = PBj> ATj> T„
Pictures and Diagrams: Once again, the students, officials 
and publishers had the same value,, Their values were 
however, significantly higher than the teachers' and 
authors, that's S = MO = PBy>T^AT0
Practical Exercises: The students and the publishers had 
the same Value,, After these Catne the mihistry offidiaia 
ahd lastly the teachers and the authors with equal values, 
that’s S * PB>MO>T = AT0
Manor Themes: Authors and teachers had the same value,,
After these came the students and the publishers also with 
equal values„ However, the values of the authors and the 
teachers were significantly higher than those of the 
ministry officials,, Ministry officials have in turn
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higher values than students and publishers, thatfrfe 
T = AT>MO>S = PB0
Physical Characteristics? Students and publishers had the 
same value. In a descending order they were followed by 
the officials then the teachers and lastly the authors, 
that’s S = PB>MO>T>AT.
Hypothesis 2 (Ho2^
Thebe is no significant difference in the cognitive, 
affective and psychomotor performances of high school 
students exposed to selected communicational strategies 
such as styles of questioning, defined technical terms, 
local specimens, labelled diagrams and pictures, inquiry 
method and challenging practical exercises and those not 
so exposedt
This hypothesis was tested using the student t̂ teSfc*
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TABLE 32
Means, Standard Deviations and t-test of the Relative Effects
of leading Questions on Cognitive Performance of"Experi­
mental and Control Group Subjects
Test Group Mean Standard
Deviation MeanDiffer—
ence t /
Ea 0.52 0.58 k V
Pre-test VS 0.10 0.78C 0.63 0.64
E1 3.29 0.85
cVS 0.44 0.68 2.85 18.50*
E1 3.29 0*85
P*st*-test vs 0.30 1.34
3*49 0.99
c 0.44 0.68
VS 3.49 0.99 3.05 19.23*E2
Pre-test E1 0.52 0.58
vs (Pre-test)vs 2.77 21.79*
Post-test E1 3.29 0.85
(Post-test)
C 0.63 0.64
Differences (Pre-test)vs
r 0.19 1.32
(post-test) 0.44 0.68
No of Cases = 48; df = 47; * * Significant Scores 
Ttable (Critical value) = 2o01; Confidence Level = 0.05 
Key: -Ê  = Experimental group 1; E^ - Experiment group 2
(No pre-test), C = Control group.
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Cognitive Performance
Leading Questions: Table 32 represents the means, 
standard deviations and t-test values of the different 
groups with respect to leading questions.
At the pre-test stage, there Was no significant 
difference between the mean scores of Experimental group
1 (E^) and the Control group (C) tc = 0.79 ̂ tfc 2.01. At 
the post—test stage however, the t-test value shows a 
significant differente between the Experimental group 1 
(E^) and Control group (C) (tc 18.50^ t^ 2.01). The
same is true of the pair wise comparison between Experi­
mental group 2 (E2) and the Control group (C). There is 
also a significant difference between the Experimental 
group 2 (E^) and the Control group C post—test scores
(fec I9#2i> fê 2.0l) ■
Since the design used in the study is a modified
Solomon -3I , Experimental group(E2)) had no pretest.
When the individual groups were considered for the 
pre-test — post-test differences, there was a significant 
difference for Experimental group 1 (E^) (tc 21.79^ t̂_ 
2o01)o In the Control group (C) there was however no
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significant difference (tc l,32<tt 2.01),
With respect to the Experimental group 1 (E^ and 
Experimental group 2 (E2)»there was no significant 
difference between their post—test scores (t 1,34-^tj. 2.01).
Since there was no significant difference in the 
pre-test scores of Experimental and Control groups, and 
since there was a difference in the post—test scores of the 
groups, the hypothesis (H02) can not be upheld.
Probing Questions? Table 33 represents the means, standard 
deviations and t-test Values of the groups with respect to 
their cognitive performance in probing questions.
As for leading questions, there is a significant 
difference between the post-test scores of groups E^ an(j 
C (tc l6075ĵ  tj. 2«01)o A significant difference also 
exist between E2 and C (tc 17,95 >  tfc 2.01) Bgsed on 
the available data, the hypothesis (H02) can not be upheld.
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TABLE 33
Means. Standard deviations and t—test of the Relative
Effects of Probing Questions on Cognitive Performance
e>f Experimental and Control group Subjects,
Test Group Mean Standard Mean t
d e v ia tio n  deinfcfeer­
E1 0*60 0.61
Pre—test vs 0.04 0.37
c 0«65 3i64
E1 2*94 0,78
vs 2*54 16.75*
c 0®40 0.61
E1 2*'94 0.78
Post—test vs 0.21 1.36
E2 3.15 0.99
C 0.61
vs 2.75 17.95*
E2 3.15 0.99
Pretest 0.60 0.61
vs
Post—test (Pvr
E
se
1test)
2.33 14.72*
Ei 2.94 0.78
(Posttest)
C 0.65 0.64
(Pretest)
Differe— Cvs 0.25 2.13*nces 0.40 0.61
(Posttest)
No, of case>s = 48} df = 47} • = Significant scoreso
ttable (Critical value) = 2. 01} Confidence level = 0.05
Key: E^ = Experimental group 1; E^ = Experimental group E^ 
(No pretest); C = Control group*
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TABLE 34
Means, Standard deviations and t-test of the Relative
Effects of Contextual Questions on Cognitive Perform­
ance of Experimental and Control group Subjects
|
Test Group Mean Standard
Deviatioh MeanDiffe- t
ence
Ei 0# 52 0.58
Pretest vs 0.02 0.15
c 0#54 0.77
E1 2#33 1.06 • .
vs 2.13 12.69*
c 0#21 0*41
E1 2.33 1.06
Posttest vs 0.22 o.i?
E2 2.55 1.17
c 0.21 0.41
vs 2.34 13.02*
E2 2.55 1.17
(PrEe1test) 0.52 0.58
Pretest vs 1.81 10.19*
vs E1 2.33 1.06Posttest (Posttest
C 0.54
(Pretest) 0.77
Differences Cvs 0.33 2.48*0.21 0.41
(Posttest)
No# of cases = 48; df =
t table (Critical value) 47; * = Significant slcevoerle s.= 2.01 ; Confidence = 0 .0 5 .
Keys * Experimental group 1; Eg = Experimental group 2 
(No pretest); C = Control group#
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Contextual Questions! Table 34 represents the means, 
standard deviations and t—test values with respect to the 
relative effects of contextual questions on cognitive 
perforroance.
There is a significant difference between the post- 
test scores of and C (tc 12.69> t 2*01), and 
hiso of E2 andj.C ((t̂  13.02^ t̂_ 2.01), consequently 
the hypothesis (Ho^) is rejected.
Defined Technical Terms: Table 35 represents the means, 
standard deviations and t-test values with regard to 
cognitive consequences of defined techhical terms.
There is a Sighificant difference between the post­
test scores of E^ arid C (tc ^tfc 2*ol) * ahd also
between E2 and C Ctc 8.02^ t^ 2.01) hence hypothesis
(Ho~4)can be upheld.
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TABLE 35
Means. Standard deviations and t—test of the Relative
Ejects of Defined Technical terms on Cognitive
Performance of Experimental and Control group Subjects
Test Group Mean Standard t
deviation MeanDiffe­
rence
Ei • .67 0.60
Pretest Cvs 0.10 0.930.56 0.65
E1 1.79 1.46
vs 1.58
C' 7.39*0*21 0*46
E1 1* 79 1*46
^osttest VS
2.00 0.20 1.78E2 1.52
c 0.21
vs 0.46 1.79 8.02*
E2 2.00 1.52
E J.Pretest L 0.67 0.60(Pretest)
vs vE.s 1.79 1.46 1.13 4.89*
posttest 1iPosttest)
c
Differ- 0.56 0.65
ences (Pretest)
CV 0.21 0.35 3.02*
(Posttest) 0.46
No. of cases = 48; df = 47; * = Significant Scores®
t table (Critical value) = 2.Cl; Confidence level - 0.05. 
Keys E^ = Experimental group 1; E - Experimental group 2 
(No pretest); C = Control group®
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TABLE 36
Means. Standard deviations and t-test of the Relative
Effects of Local specimens on Cognitive Performance
of Experimental and Control group Subjects
Test Group Mean Standard Mean tDeviation Differs
ence
Ei
Pretest vs 0*02 0*24C 0.31 0.55
Ei 4*46 0,77
vs 3.63 23.16*
C 0*83 0*81
Ei 4*46 0.77
Posttest vs 0.20 1.79
E2 4.66 0*91
C 0*83 0,81
vs 3*83 24*85*
E2 4*66 0*91
E1 0*29 0*50Pretest (Pretest)
vs vs 4*17 33.61*
Po^fetest 4.46 0.77(Postiest)
C 0.31 0*55
(Pretest)
Diffe- vs 0.52 4.01*
rences C 0.83 0.81(Posttest)
No* of Gaaee * 48; df = 47; * = Significant scores, 
ttable (Critical value) *= 2*01; Confidence level = 0*05* 
Key: E^ = Experimental group 1; E2 = Experimental group 2
(No pretest); C = Control group*
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Local Specimens: Table 36 represents the means, standard 
deviations and t—test values with respect to the cognitive 
performances of the subjects as a result of using local 
specimens.
There is a significant difference between the post—test 
scores of E^ and C (tc 23.16^ t̂. 2.01)^ and also between 
B2 and C (tg 24.85 > tfc 2.01).
Labelled diagrams and pictures: Table 37 represents the 
means, standard deviations and t-test values relative 
to the subjects cognitive performance oh labelled diagrams 
and pictures.
There is a significant difference between the post­
test scores of E^ ahd C (tc 25^06^ 2#0l)and between
E_2  and C (tc 26.94> t. 2.01).
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TABLE 37
Heahs^ Standard deviations and t-*test of the Relative
Effects of Labelled Diagrams and Pictures on Cognitive
Performance of Experimental and Control group Subjects
Test Group Mean StandardDeviation MeanDiffer­ t
ence
E1 0.46 0.62
Pretest Cvs 0.06 0.440.52 0.74
E1 4.71 0.54
\/s 3.67 26.06*
c 1.04 0.92
E1 4*71 0.54 1
Posttests vs <5*57 0*09 0.63
c 1*04 0*92
VS 3.76 26.94*
E2 4.80 0.57
Pretest
vs E1
0.46 0.62
Posttest (Pretest)vs 4.71 0.54 34.12*E1
(Posttest)
Differ^- C 0.52 0.74(Pretest)
vs 0.52 3.00*
C 1.04 0.92
(Bosttest)
No, of cases - 48; df = 47; * = Significant scorese
KttaVb! leE.  (=c riEtxipcearli mevnaltuael) g-r p  i ou
2p. 011;; CEo_ nf= idEexnpceerimleenvteall =gr0.o0u5p. 2
1
(No pretest); C = Control group.
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TABLE 38
Means ̂ Standard Deviations and t-test of the Relative
Effects of Inquiry Method on Cognitive Performance
of Experimental and Control group Subjects
Test Group Mean Standard Mean
Deviation Differ­ t
ence
E1 0.61
Pretest Cvs 0o 52 0.060.62 0.50
E i 1»23 1.13
vs
c 0o27 0.45 0.96 5*69*
E ! 1*23 i.13
Posttest Vs
1*17 0.06 1.00e2 l«id2
c Oo 27 0.45
vs
1067 0.90 5.22*E2 1.12
E1 0.61
PreV  tb est (Pretest)vEsi 1.23 0*65 3.29*Posttest 1.13(PosCttest) Oo 52
(Pretest) 0.62
differ- vs
ences C 0.27 0.250.45 2*29*
(Posttest)
Noo of case2 S  = 48: df = =4 7; *  =ttable (Critical value) SignificantKeys Ê _ =  Experimental 2.01;
scores 0
Confidence 0.05.
group 1; level =E2 =  Experimental group 2
(No pretest) , C = Control group,,
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Inquiry Method: Table 38 represents the means, standard
deviations and t-test values with respect to the subjects 
• icgnitive performance on the inquiry method®
There is a significant difference between the post­
test scores of E^ and C (ltc 5.69 ̂  t̂. 2*01), and between 
and C (tc 5*22 > tfc 2.01).
Challenging Practical Exercises: The data in Table 39
represents the means, standard deviation and t-test values
in terms of th*e subjects cognitive performance with respect 
to challenging practical exercises®
There is a significant difference between the post­
test scores of and C Ctc 24.73> tfc 2.01), and between 
Eg and C u d 24*72 } 2*01) hehce the hypothesis (H02)
can not be upheld*
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TABLE 39
Means, Standard deviations and t-test of the Relative
Effects of Challenging Practical Exercises on Cognitive
Performance of Experimental and Control group Subjects
Test Group Mean StandardDeviation MeanDiffer­ t
ence
Ei 0.60 0.57
Pretest vs 0.08C 0.640o52 0.68
Ei 3.94 0.73
vs 3*23 24.73*
c 0o 71 0.71
E1 3.94 0.73
Posttest vs 0.02 1.00
E2 3«96 0.74
C 0.71 0.71
3.25 24.72*
E2 3.96 0.74
0.60 0.57
Pretest
vs (Pretest)
Posttest vs 3.33 28.59*E 3.94 0.7^(Pos1ttest)
C 0.52 0.68
differ- (Pretest)vs c. -ences 0.19 1.42C 0.71 0.71
(Posttest)
....................................
No of cast2S = 48; df = 47; * = Significant scores.
ttable (CrEixtpiecarli mevnatlue) = Keys E^ = al grou
2p.0 11;; Confidence level = 0 .0 5 .E2 = Experimental group 2
(No pretest); C = Control group,.
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TABLE 40
Means. Standard deviations and t-test of the Relative
Effects of Questioning styles on Affective Performance of
Experimental and Control group Subjects
■Lest Group Mean Standard t
Deviation MeanDiffer-
ence
Ei 0.75
Pretest Cvs 0.130.62 0.64 1.35
E1 5.00 0.90
Cvs 0.83 4.12 22.90*0.72
Ei 5.bo 0.90
Posttest vEs
i 0.00 0.00
2 5.00 0.92
C 0.83 0**72
Vs 4.12 24.24*
E2 5.00 0.92
Pretest (PrEeatests) 0.75 0.70
vs
Posttest vs 5.00 0.90 4.30 27.73*
(Positest)
C 0.63 0.64
(Pretest)
Differ
Cvs 0.21 1.65ences 0.83 0.72
(Posttest)
No. of cases = 48; df = 47; * = Significant scores.ttable (CriEtxipcearli mevnaltue) = KeyJ E^ = al grou
2p. 011;; CEon f= idEexnpceerimleenvteall =gr0.o0u5p.2  2
(No Pretest) ; C = Control group.
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182
Affective Performance
Questioning Styles: Table 40 represents the means, 
standard deviations and t-test values of the subjects 
with respect to their affective performance on 
questioning styles*
There is a significant difference in the post­
test scores of and C (fcc 22.90 t^ 2.01) and
between EL 2 and C (t c 24.24 )> t t 2.01) hence hypothesis 
(Hog) can not be upheld.
Defined Technical Termst Table 41 represents the means, 
standard deviation and t—test values of the subjects
with respect to their affecti ive .p..e.r formance•  ro n'  ' • d’efined 
technical terms.
There is a significant difference between the post- 
test scores of and C (t 20.47 > tt 2*01)* and between 
and C (tc 21.11 "̂ 2*01), hence fiypothefeis (Hc^) is
rejected.
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183
TABLE 41
M eans, Standard deviations and t-test of the Relative
Effects of Defined Technical Terms on Affective
Performance of Experimental and Control Group Subjects
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16k
TABLE 42
Means. Standard Deviations and t-test of the Relative
Effects of Local Specimens on Affective Performance
'erf Experimental and Control group Subjects
Test Group Mean Standard Mean
Deviation Differ­
ence t
E1 0.65 0.60
Pretest cvs 0.100.54 0.54 1.15
E1 5.21 0.65
Cvs 4.48 38.86*0.73 0.57
Posttest H £.21 0.65
0.02 0.1*7
5.19 0.67
d 0*73 0.51
vs 4.46 35.33*
E2 5.19 0.67
0.65 0.60
Pretest (Pretest)
vs vs 4.56 35.24*
Posttest 5.21 0.65
(PosEt1test)
C 0.54 ' 0.54
Differ— (Pretest)
ences vs • .19 1.64C 0.73 0.57
(Posttest)
No. of cas
ttable (Criets ic=a l4 8;v aldufe )= 47; * = Significant scores.= 2.01; Confidence 1evel.= 0© 05©
Key; E^ = Experimental group 1; E^ Experimental group 2 
(No pretest) ; C = Control' group.
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Local Specimens: Table 42 represents the means, standard
deviations and t-test values of the subjects with respect 
to their affedtive performance when local specimens are 
used in teaching,,
There is a significant difference between the post­
test scores of E^ and C (tc 38»86^> tfc 2*01), and between 
E 2 and C (tC  35*33 t,t  2*01), hence hypothesis (Ho £) is
rejected*
Labelled Diagrams and Pictures: Table 43 represents the 
means, standard deviations and t-test values of the 
subjects with respect to their affective performance 
t in labelled diagrams and pictures*
There is a significant difference between the post** 
test scores of E 1 and C (fĉ  35*96> 2*01) dnd between
B2 an<3 c ^ * 00^  ^  2*01), hence hypothesis (Hog) can
not be upheld*
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TABLE 43
Means. Standard deviations and t-test of the Relative
Effects of Labelled Diagrams and Pictures on Affective
Performance of Experimental and Control group Subjects
Test Group Mean StandardDeviation Mean tDiffer­
ence
\
Ei 0.71 0.71
Pretest vs 0.13 1.14
c 0.58 0.68
E1 5.67 0.48
vs 4.88 36.96*
c 0.79 0.65
E1 54.6*7 0*48
PoSttest vs 0.00 0.00
E2 5.67 0.48
c 0.79 0.65
vs 4.88 39.00®
E2 5.67 0.48
Ei 0.71 0.71
Prevstest (Pretest)
Posttest vs 4.96 40.44*
E1 5.67 0.48
(Posttest)
C 0.58 0.68
(Pretest)
Differ-
ences Cvs 0.210.79 0.65 1.49
(Posttest)
No. of cases = 48; df = 47; • «= Significant scores 
Ktetya:b leE ^ (sC rEitxipcearli mevnaltuael)  g=r ou2p. 011,;  CEo2 nf= idEexnpceer imleenvteall  = gr0.o0u5p.  2 
(No pretest); C * Control group.
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TABLE 44
Means. Standard deviations and t-test of the Relative
Effects of Inquiry Method on Affective Performance of
Experimental and Control group Subjects
Test Group Mean StandardDeviation MeanDiffer­ t
ence
Ei 0#6& 0.61
Pretest Vs 0.02 0.23
c 0.60 m0.57
■
E1 4.50 1.09
VS 3.85 20.22*
s 0.65 0.64
E1 4.50 1.09
Posttest VS 4.63 0*13 0.68H 1*08
c 0.65 0.64
vs 3.98 21.54*
E2 4.63 1.08
0.58 0.61
Pretest E.(PreJlvs test)
Posttest V B 3.92 22.96*E1 4.50 1.09
Dif f er— (Posttest)
ences C 0.60 0.57
(Pretest)
Cvs 0*040.65 0.64 0.36
(Posttest)
No© of cases = 48; df = 47; • = Significant scores 
ttable (Critical value) = 2.01; Confidence level = 0.05. 
Key: E^ . Experimental group 1, E2 . Experimental group 2 
(No pretest); C = Control group.
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Inquiry Method: Table 44 represents the means, standard
deviations and t-test values of the subjects with respect
to their affective performance using the inquiry method.
There is a significant difference in the post—test 
scores of and C (tc 20,22^ 2.01) and between
Eg and C (tc 21,51 } t̂. 2,01) hence hypothesis (Hog) is 
rejected.
Challenging Practical Exercises: Table 45 represents the 
means, standard deviations and t-test values of the subjects 
with respect to their affective performance on challenging 
practical exercises.
There is a significant difference in the poSt<-test 
scores of and C (tc 26«j34^ 2*01) j arid between E _
and C (fcfc 29,01^ 2,01), hence hypothesis (Hog) is
rejected.
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TABLE 45
Effects of Challenqinq Practical Exercises on Affective
Performance of Experimental and Control qroup subiects
Test Group Mean StandardDeviation Mean tDiffer-
ence
E1 0.73 0.54
Pretest vs 0.13 1.35C 0.60 0.57
E1 3.58 0.50
cVS 0.67 0.52 2.92 26.34*
E1 3.58 0.50
Posttest VS7? 0.02 0.22E2 3.56 0.50
c 0.67 0.52
vs 3.56 0.50 2.90 29.01*E2
E1 0.73 0.54Pret (Pretest)vsest vs 2.85 28.92*
Posttest E1 3.58 0.50
(Posttest)
C 0.60 0.57
differ- (Pretest)
ences Cvs 0.07 0.550.67 0.52
(Posttest)
No. of cases * 48; df = 47; * * Significant scores* 
ttable (Critical value) = 2*01; Confidence level = 0o05c 
Key: E 1 » Experimental group 1; E2 = Experimental group 2 
(No pretest); C = Control group*
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TABLE 46
Means. Standard Deviations and t-test of the Relative
Effects of Physical Characteristics on Affective
Performance of Experimental and Control group Subjects
Test Group Mean StandardDeviation Mean tDiffer­
ence
Ei 0.75 0.64
Pretest Cvs 0.04 0.390.71 0.58
Ei 4.75 1.00
cVS 3.92 21.67*0.83 0.60
E1 4.75 1.00
Posttest vs 4.75 1*00 0.00 0.00E2
C 0.83 0.60
vs 3.92 23.69*
E2 4.75 1.00
E1 0.75 0.64
Prevstest
(Pretest)
Posttest vs 4.75 1.00 4.00 23.39*
(PostEt1est)
C 0..71
differ- 0.58
ence (Pretest)Cvs 0.83 0.60 0.13 1.06
(Posttest)
No. of cases = 48; df = 47; * =
ttable (Critical value) Significant scores.= 2.01; Confidence level = 0.05.
Key: E^ - Experimental group 1; E = Experimental group 2 
(No pretest); C = Control groupe
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Physical Characteristics: Table 46 represents the means, 
standard deviations and t-test values of the subjects with 
respect to their affective performance on the textbooks 
physical characteristics,,
There is a significant difference in the post-test 
scores of E^ and C (tc 21*67^ t̂. 2,01) and between E2 
and C (t 23.69> tt 2*01), hence hypothesis (Ho2) is 
rejected*
Psvchomotor Performance
’ ■ Table 47 represents the means, standard deviations 
and t-test values of the subjects with respect to their 
psychomotor performance on the communicational strategies 
used by the textbooks*
There is a significant difference between the post-test 
scores of E^ and C (tc 31*37^ t̂. 2*Q1), and between E2 
and C (tc 30*74^ t̂. 2*01), hence hypothesis (H02) is rejected* 
Hypothesis 3 (H03)
There is no significant difference in the readability 
indices of the four textbooks: Mackean, Ewusie, Stone and 
Cozens and STAN Biology used for the study*
This hypothesis was tested using analysis of variance 
and Tukey*s post-hoc test*
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TABLE 47
Means. Standard deviation and t-test of the Relative
Effects of Communicational Strategies on Psychomotor
Performance of Experimental and Control group Subjects
Test Group Mean StandardDeviation MDeiafnfer­ t
ence
E1 2.58 2.21Pretest vs o.io
c. 2*48 2.25
E! 17.04 2.09
vs 14.04 31.37*
c 3.00 2.22
E1 17.04 2.09
Posttest Xs 1.02 0.8718,06 7.56
C 3.00 2.22
vs
18.06 7.56 15*06
30.74*
E2
E1 2.58 2.21
Pretest (Pretest)
vs vs 14.46 35.05*
Posttest E1 17.04 2.09
(Posttest)
C 2.48 2.25
Differ- (Pretest)
ence Cvs 1.133.00 2*22
(Posttest)
Noo of cases = 48; df = 47; * = Significant scores* 
ttable (Critical value) = 2*01; Confidence level = 0*05* 
Key: E1 = Experimental group 1; E2 „ Experimental group 2
(No pretest); C = Control group*
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CM
O0
iCMn
Oc
193
TABLE 48
Means, Standard deviation of Readability Scores for 
the Four Biology Textbooks
Textbooks Pages Mean StandardDeviation
ST i 20 72.50 1.69
(EasyO
MK 20 74*19 1.72
(Easy)
EW 20 52.03 1.98
(Standard)
SC 20 55.53 0.73
(Standard)
Key: ST = STAN BIOLOGY: MK = MACKEAN
EW = EWUSIE: SC = STONE AND COZENS
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TABLE 49
Readability Value Interpretation of the Four Biology 
Textbooks (Using Wahome (1979) Interpretation Data
Readability 70-79 60-69 50-59 40-49
Average
Sentence
Length 14 17 21 25 t
Syllables 
Per 100 
Words 139 147 155 167
Descrip­
tion of 
style Easy Faitly Standard Fairly
(4th Year easy Difficult
students)
..........................
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Table 48 represents the mean readability values of 
all the textbooks. Table 49 provided is for the interpre­
tation of values in Table 48. It is an adapted Wahome 
(1979) interpretiation data relative to Nigerian schools 
for 4th year biology students.
As shown in Table 48, Mackean has the highest readability 
index of 74,19, followed by STAN Biology 72,50, then Stone 
and Cozens 55,56 and lastly Ewusie 52,03.
The mean readability values were consequently inter­
preted using Table 49 for each textbook appropriateness 
to the subjects involved in the study. Consequently,
Mackean was found to be easy, so also was STAN Biology.
Stone and Cozens ahd Ewusie were also £o\ind to be standard
ti extbooks*
ihiS interpretation of the textbooks average Readability 
indices shows that all the textbooks would be adequate for some 
of the Form Four students in Nigerian Secondary Schools. 
However, when the readability indices were subjected to the 
analysis of variance and Tukey's a posteriori test a better 
picture of the textbooks adequacy to biology learning is
revealed.
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TABLE 50
Summary of the Analysis of Variance of the Four Biology 
Textbooks Readability Values
Measure Source SS df MS F
Between 7382.09 3 2460.70
9.72*
Within 19252.35 76 253.52
Readabi-
lity
Total 26634*44 ^9
\
TektbookSi £!TAN BIOLOGY: MACKEAN: EWUSIE : STONE AND COZENS
Ftable (Critical value) = 4013; ©< -Level = 0.001. 
• » Significant Scores*
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The summary of the analysis of variance on the text­
books readability values is provided in Table 50,
On the basis of the F—values, it has been established 
that there are significant differences in the mean reada­
bility values of the four textbooks (F 3, 76 = 9071,
p <  0,001),
TABLE 51
Summary of Tukev1s a posteriori procedure on Readability 
Values of the Four Biology Textbooks
Measure Range of Significant Values
Readability MK(73*,51)>S'1(72,13) > SCC55,38)> EW(52*04)
1
Key: ST = STAN BIOLOGY: MK = MACKEAN
EW = EWUSIE: SC = STONE AND COZENS,
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These significant differences were further subjected 
to a posteriori contrasts test. The application of Tukey’s 
test indicates that these ’Honestly Significant Differences’ 
lie as shown in Table 51®
Mackean was found to be significantly better than 
STAN Biology® Others were in the order of Stone and 
Cozens and lastly Ewusie*
The performance of the textbooks was in the order of;
MK >  ST >  SC >  EW.
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CHAPTER SIX
DISCUSSION OF RESULTS, CONCLUSION« IMPLICATIONS AND 
RECOMMENDATIONS
Discussion of Results
In this section, the several interesting findings 
which have emerged as a result of the present investigation 
are placed within the framework of previous studies*
Additional insights that are provided about the relative 
effects of communicational strategies in biology textbooks 
on learning are discussed*
It has been considered logical to approach the discussion 
of the results in line with the hypotheses posited in the 
study«
As indicated in Chapter 3, the Solomon »3 Group Design 
w§s used* That is, the same treatment was used for 
experimental groups 1 (Ê ) and experimental group 2 (Eg)*
Since there was no significant difference between E^ and Eg 
on all the Variables contrasted, the discussion henceforth «-.'i 
will be done in terms of similarities or differences 
between the two experimental groups (that is E^ and E^) on 
the one hand and the control group (C) on the other. The 
various categories compared as well as the conclusion,
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implications and recommendations are presented below based 
on the following categorisation:
(a) Questioning styles relative to cognitive, affective 
and psychomotor performances of students.
(b) Defined technical terms, local specimens labelled 
diagrams and pictures, inquiry method and challenging 
practical exercises relative to students cognitive, 
affective and psychomotor performances*
(c) Roadability of textual materials®
Cd) Conclusion.
(e) Implications.
(f) Recommendations.
Questioning styles relative to cognitive, affective and 
psvchomotor performance of students
A question raised in the study is whether or not there
are any significant differences in the frequehdy of questioning
styles used by the four biology textbooks involved in the
study.
An examination of the findings of the present study 
shows that there are significant differences in the textbooks 
with respect to the status of factual, probing, leading,
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introductory and terminal questions* It was also found 
that contextual questions were present only in Mackean, 
while the other textbooks contained none* However, more 
of the textbooks contain rheotorical questions.
The analysis of the questioning styles in the study 
revealed that Mackean tends to excel other textbooks in 
its use of questions. Mackean contained more factual, 
leading, probing and terminal questions than the rest of 
the textbooks examined in this study. This is however not 
to day that MaCkean-'has attained the required standard in 
question asking, or that it is superior in every case Where 
certain types of questions have been warranted.
Although frequency per se does not necessarily deter­
mine the quality of a given text, in certain cases — especially 
where questions are hard to come by as in this study, a 
high number or level of questions asked might serve as a 
useful indicator of textual quality.
As discussed in Chapter 2 and in view of current 
emphasis in science education, a meaningful inquiry can not 
be achieved without the use of appropriate questions. While 
the texts (apart from STAN Biology which is new) have made
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some improvement over their former editions with regards 
to questions (Ogunniyi, 1982), they are still far short 
of expectation as far as high*order questions are concerned. 
The responses of producers and consumers of biology 
textbooks, showed that there are significant differences 
in the views of authors, publishers, ministry officials, 
teachers and students about questioning styles used in 
the biology textbooks examined in this study. Students, 
officials and publishers on the one hand tend to share a 
similar viewpoint, while authors and teachers on the other 
tend to express a viewpoint that is different from the 
former. This disparity of viewpoints certainly has great 
implications for science teaching ahd learning. It seems 
that while the authors and the teachers who use their product 
are agreed, the sellers (publishers) and the consumers 
(students) and those saddled with the responsibility of 
planning the right type of education (officials) are 
operating on a different premise. This should not be the 
case. The communication gap between the two sets of groups 
requires a closer attention to ameliorate the situations,
A question also raised in the study is whether or not
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there is any significant difference in the cognitive, 
affective and psychomotor performance of high school students 
exposed to selected questioning styles and those not 
exposed*
The cognitive consequences of such questioning styles 
as leading, probing and contextual, indicate significant 
differences between the experimental and control groups*
The experimental groups performed better than the control 
group after they have been exposed to leading, probing and 
contextual questions.
With respect to affective and psychomotr performances, 
there are significant differences between the experimental 
and control groups. The experimental groups performed 
better than the control group*
The findings in this study bear some relationship to 
previous research efforts on the merit of questions to 
learning. The analysis of the textbooks as reported in the 
earlier chapter, showed that they contain mostly factual 
questions. This finding is in agreement with earlier 
findings in the area Ce.g. Carrick, 1977; Lowery and 
Leonard, 1978; Ogunniyi, 1982). Good as factual questions
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are for recall purposes, they flo not seem to be suitable 
for high cognitive activities. Generally, they tend to 
encourage rote or superficial learning at the expense of 
deeper intellectual thought (Gall, 1970; Ogunniyi, 1981;
1982; 1983; 1984).
There is a striking similarity on leading and introduct­
ory questions in STAN Biology and Ewusie. The affinity of 
these two textbooks is an apparent deviation from Ogunniyi*s 
(1983) finding that the nationality of the authors did not 
affect the communicational styles in the four textbooks 
he examined. Perhaps the situation is that the hationality 
of an author does affect his style of communication. This 
is more so when the content of the science under study 
(in this case biology) has a considerable amount of local 
in-put. Certainly, more studies are required to determine 
the effect of cultural background on an author's style of 
communication.
Another important issue is the fact that Macfeean was 
the only textbook that contained contextual questions.
This is dissappointing considering the merit that have been 
associated with this type of questions. Carrick (1982) and
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Ogvmftiyi (1982) have asserted that contextual questions 
tend to promote the development of: (1) problem-solving 
attitude, (2) observational and mental recognition of critical
I
ideas of a given subject matter, (3) focussing the reader 
on the issues at stake, and (4) reinforcement of learning etc* 
If these values and merits of contextual questions in 
biology learning is to be realised, there is the need for 
more of these questions in biology textbooks.
The crucial question, however, is to determine which of 
the questioning styles is the most adequate in promoting 
biology learning. A comparative study of these questioning 
styles might help to determine what question is more suitable 
for a given context. At this exploratory stage, all that 
can be said is that the textbooks analysed in this study do 
not seem to place sufficient etnphasis on the so-called high- 
order questions such as probirig, leading and contextual 
questions.
The variation in the responses of authors and teachers 
on one hand, and officials, publishers on the other may be 
related to their role perception in the education enterprise* 
Since the individual group experiences and expectations
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largely depend on the roles they are suppose to play, they 
are likely to percieve situations and tasks varyingly.
It is a likely premise to expect authors and teachers as 
ihitiators and facilitators of learning to be concerned 
with the place of questioning in the learning process and 
learning outcomes. On the other hand, students and officials 
may often assume questions in the evaluatory process of 
testing learning outcomes.
The better performance on the cognitive and affective 
instruments by the experimental groups than the control 
group agrees with De Cecco (1964) and Balogun (1974) that 
questioning styles as mediators in learning, can also 
serve as a crucial evaluation tool in assessing learning*
The significant difference exhibited by the experimental 
and control groups is a further demonstration of the 
relative advantage of well sequenced questions in a learning 
episode over the *chalk and talk' lecture method devoid of 
stimulating questions - a situation akin to what Nuthall and 
Lawrence (1968) refer to as the superiority of the direct 
mode over the indirect mode of teaching.
The better performance of the experimental groups can 
also be attributed to the fact that questions generally
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influence learning not only by their position and type in a 
textual material, but also by their contiguity to related 
content materials (Balogun, 1974; Leonard and Lowery, 1978; 
Carrick, 1982)„ The value of leading and probing questions 
as stimulators of inquiry behaviours (Carrick, 1982;
Ogunniyi, 1982) has once again been confirmed in the present 
study» That is, the differential performances between 
the experimental and control groups may not be unrelated 
to the variety of stimulating questions used in teaching 
the experimental group subjects as compared to the traditional 
styles used for the control group«
While factual questions could lead to higher order 
questions, their overuse tend to trivalise learning 
(Ogunniyi, 1982). To Gall (1970), instruction in facts can 
also be achieved through programme instruction. Since all 
authors claim to emphasize inquiry in their prefaces, one 
would have expected more thought—provoking questions than 
was encountered in their actual reading Content. A probable 
reason for the oVeruse of faCtUal questions is that the 
final School Certificate Examination still emphasizes mainly 
factual questions. Weaver (1964) contends that students 
are prepared for examination rather than life after school*
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This situation has been shown to be true in this study.
Defined technical terms, local specimens, 'labelled 
diaqrams/pictures. inquiry methods and challenging 
practical exercises relative to students cognitive, 
affective and psvchomotor performances
The question was raised in this study with respect 
to whether or not there are any significant differences 
in the way that the textbooks use technical terms, 
major themes, diagrams/pictures, specimens and practical 
exercises. Also, the preferences of publishers, authors, 
ministry officials, teachers and students for these 
strategies were examined. Ahother area of interest was to 
analyse the performance of students who have been exposed 
to the same Set of strategies and those who have not had 
such exposure. In the subsequent sections, we shall examine 
each of the strategies in greater detail.
Technical Terms
The findings in the study show that there were signifi­
cant differences in the way the textbooks define technical 
terms. The study established that Mackean had the highest 
representation of technical terms. There were significant 
differences in the way the four textbooks use technical
terms.
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209
It is gratifying to note that there were no 
significant differences ih the Views of authors, publishers, 
ministry officials * teachers ahd students with respect to 
the Way technical terms should be defined* This shows 
that the producers and consumers of these biology text­
books share basically the same View in the area*
The study also revealed that the experimental groups 
who were exposed to well defined technical terms performed 
better in the cognitive, affective and psychomotor tasks 
than the control group who were denied of such an 
exposure*
The better performance ofi  the experimental groups lends
support to Evans* (1976) assertion that technical terms 
should be defined so that they can be of value to learning# 
This is because definitions of technical terms eliminates 
the ambiguity often associated with language, since every 
definition can be identified, isolated and recognised as 
clarifying meaning in the learning process. As Ogunniyi 
(1982) and Carrick (1983) have noted, Well defined 
technical terms help to eliminate ambiguity, and to pave 
way for meaningful communication#
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Unlike Evans' (19*76) and dgunniyi's (1982) suggestion 
that technical terms be defined at their first occurrence, 
the producers and consumers of biology textbooks involved 
in this study are not definitive as to when technical 
terms should be defined in a given textbook® It is 
desirable that further studies be carried out to ascertain 
the relative impact of the timing in which technical 
terms are defined®
Fortunately* all the four textbooks made attempts to 
define technical terms as soon as they occur. There are 
occassions, however, when they deldyed in doing so®
Ogunniyi (1982) had earlier enumerated the advantages and 
disadvantages of defined technical terms® He observed 
that defined technical terms at its first occurrence 
reduces ambiguity, stimulates and sustains reading interest. 
On the otherhand, undefined technical terms increases 
reading difficulty and reduces attention and comprehension. 
Sometimes, however, a delayed definition may encourage 
suspense and reflection on the part of the reader. Where 
students are used to rote learning, they have a tendency 
to cram definitions rather than try to find out the
UNIVERSITY OF IBADAN LIBRARY 
meaning of an unfamiliar technical term.
As with questioning styles, one observes that there 
were significant differences in the four biology text­
books in the way they present technical terms. Observably 
however, is the affinity between STAN Biology and Ewusie 
on one hand? and Mackean and Ewusie on the other in the 
w§y they present technical terms. The similarity can be 
associated with the authors country of domicile in addition 
to their interests, values, experience and training.
Local Specimens
■thebe are significant differences in the specimens 
dohtained in the four tektbooksw This diffebSnce may be 
a reflection of quantity tHan ahything else. But despite 
this, the textbooks contained mostly local specimens. 
Comparatively, STAN Biology contained a greater number 
of local specimens than the others.
There were also significant differences in the views 
expressed by authors, teachers, students, publishers and 
ministry officials about specimens used in biology textbooks. 
However, as expected, authors and teachers have similar 
responses different from the others. Although the reasons
UNIVERSITY OF IBADAN LIBRARY 
212
for this disparity of viewpoints are not evident at this 
exploratory stage, further inquiries are necessary 
before a clearer picture can be obtained,, It should 
however be possible to identify valid criteria for 
determining a range of local specimens to be included in 
a given textbook0 For example, a biology text as STAN 
Biology containing between 95—90% local specimens may 
be judged adequate. Certainly, more studies are needed 
to establish what range would be suitable in terms of 
specified objectives.
The experimental groups exposed to local specimens 
performed significantly better than the control group 
subjects whose attention was not specifically directed to 
the same specimens.
The place of local specimens in biology teaching can 
hot be over-emphasized. The better performance exhibited 
by the experimental group subjects has further confirmed 
Ogunniyi*s (1982) view that local specimens when used in 
biology teaChihg can promote learning and ehhance students 
understanding.
This fact seems to have been appreciated by all the 
authors of the biology textbooks examined in this study.
UNIVERSITY OF IBADAN LIBRARY 
213
They all used local specimens quite generously,, Since 
these specimens are located in the students' environment, 
they can be obtained easily, explored sufficiently and 
studied adequately than foreign specimens which are 
rarely available or too costly to obtain* Their availa­
bility when needed makes teaching and learning of biology 
less tedious, interesting and relevant,,
Labelled diagrams and pictures
There were significant differences in the frequency 
of diagrams and pictures contained in the biology text­
books* The textbooks contained mostly diagrams — particu­
larly labelled diagrams* The few pictures in the text­
books were generally unlabelled* Generally, Mackean 
contained more labelled diagrams than the other textbooks* 
There were also significant differences in the views 
of authors, publishers, ministry officials, teachers and 
students with respect to diagrams and pictures in biology 
textbooks* As probably expected, authors and teachers 
have similar responses, 4uite different from those of 
students, publishers and officials. This is not a surprising 
finding because one probably expects that it is a known 
fact that pictures and diagrams in the teaching-learning
UNIVERSITY OF IBADAN LIBRARY 
214
process aid in conveying meaning. Particularly, they are 
capable of explaining concepts, features and physiological 
functioning in biology without using language that may 
distort learningo Their importance underscores the 
great need to bridge the gap between instructors and 
learners on their merits and demerits in learning,.
The study also revealed that thd experimental groups 
performed better than the control group with respect to 
labelled diagrams and pictures.,
The better performance exhibited by the experimental 
groups has affirmed the merit of labelled diagrams and 
pictures in biology learning® According to Ogunniyi (1982), 
pictures and diagrams can through their form, clarify, 
colour and adequacy enhance communication and complement 
written and verbal instructions® Also, the study lends 
support to Reid*d and Miller’s (1980) assertion that 
pictorial representations facilitate learning, makes 
learning interesting, sustains the learner’s interest and 
enhance the students power of observation®
The better performance of the experimental groups 
demonstrates that labelled diagrams and pictures are
UNIVERSITY OF IBADAN LIBRARY 
215
indispensable memory aids® According to Evans (1976), 
labelled diagrams are essential in biology in explaining 
an anatomical and morphological featur- , while inadequate 
and unlabelled diagrams often create communication gaps®
However, Egbugara (1983) asserted that pictures 
when used as advance organisers are effective in enhancing 
students achievement® The issue therefore is to determine 
if diagrams, pictures or their combination are adequate in 
enhancing students performances® This is an area that 
could be further explored®
Inquiry Method
Although virtually all the themes were well represented 
in the textbooks (the only exception is the traditional 
world-view present only in STAN Biology) there are 
significant differences in the major themes used in the 
textbooks® STAN Biology however contained the highest 
number of themes®
In addition* there are also significant differences 
in the views of authors* teachers, publishers, ministry 
officials and students on major themes used in biology in 
the textbooks® Ohiy stUdehts ahd publisher^ have similar
responses®
UNIVERSITY OF IBADAN LIBRARY 
216
Furthermore, the experimental group subjects 
performed significantly better than the control group 
subjects relative to the inquiry method used in the study* 
This fihding has come to justify the potential of inquiry 
technique^ for the teaching and learning of biology*"'
For the past two decades, science educators have 
emphasized the presentation of biology as a form of Inquiry* 
Cooper and Petroskey (1974) emphasized that science 
subjects should be presented in an inquiry model to make 
the subject interesting to students*
However, science educators have observed that there 
are other themes that are significant to biology learning*
De Maris (1965) study supports the use of historical 
themes in the presentation of learning materials to 
enhance students understanding* Good as faT historical 
approach may be, however, it is important that biology 
teaching and learning be tailored to meet societal
... v_ ' •*Cs
prevailVirn)• g,-:' V needs* *•- v', V«’
This is perhaps the reason why Ogunniyi (1982) has 
recommended a greater emphasis on "ecological" and ^economic 
importance" themes especially in view of the prevailing
UNIVERSITY OF IBADAN LIBRARY 
217
economic problems in Nigeria coupled with the mounting 
ecological problems facing the nations flora and fauna*
In addition, although evolution is a central issue 
in biology, because of the role and place of religion 
in traditional African settings, teachers should be 
cautious in teaching evolutionary themes* Religion has 
come to be respected as a way of life, and nothing should 
be done to cause learners’ disaffection towards the study 
of biology*
Researchers have also recognised the role of myth 
as critical component of African cosmology in relation to 
modern science, Idowu (1962; 1967), Horton (1964; 1971), 
Abraham (1967) and Fernandez (1972) have noted that myths 
are exploratory mechanisms and organising metaphors used 
by Africans to solve the puzzles of nature* Idowu (1962), 
specifically observed that, "myths serve the manifold 
purposes of statements of doctrinal beliefs, confirmation 
of faith in mind, lithurgical credo and simple metaphysics"* 
Bascom (1965), perhaps has put the situation clearer for 
the traditional African culture. He observes that myths 
account for the origin of the world, of man, of death, and
UNIVERSITY OF IBADAN LIBRARY 
218
they may account for the founding of a tribe, an ethnic 
group or a clan or lineage,, Therefore, to teach science 
without paying attention to the critical cultural variable
of myth is to present an u,n wholeso.m e World—v; . ii ew t' o-- the 
students*
Horton (1962) however, observed that the difference 
between the scientific and African thought system is that 
the latter lacks a body of explicitly stated 'acceptance/ 
rejection criteria,, While the former chooses things, the 
latter tends to choose people as the basis for its 
explanatory models. While the latter position is true, 
Ogunniyi (1984) contends that the former can not be true 
since even within a tribe,there are several versions of 
the same myths depending on the locality. These various 
versions are the products of certain forms of "acceptance/ 
rejection criteria".
As Ogunniyi (1984) contends, the African and the 
scientific thought systems are explanatory mechanisms or 
organising metaphors used for interpreting natural phenome­
non and to order human activities. To Ogunniyi, modern 
science can be meaningfully introduced to the African, only 
if his cosmological viewpoint is borne in mind. Idowu (1970)
UNIVERSITY OF IBADAN LIBRARY 
2±$
cautioned, that any one aspiring to bring social benefits 
to the African should be aware of his cultural beliefs 
and practices* These studies underscore the importance of 
traditional world-view in biology teaching,, The teachers 
should be aware of the central issues involved in 
traditional African cultural beliefs and practices and 
explore these to explain scientific concepts and findings*
He should be able to tease out the similarities and the 
differences of the two viewpoints of the world* As 
previously observed, themes in biology learning should 
be a way of disseminating knowledge and clarifying meanings* 
But this objective can not be achieved unless the themes 
used are properly organized and are relevant to the learners1 
environment*
Challehqinq ■ practiced exerci sê s i - s
Although all the different categories of practical 
exercises examined were well represented in the textbooks, 
there are significant differences in the way they are 
represented in the textbooks* Stone and Cozens had the 
largest number of challenging practical exercises*
With respect to practical exercises contained in
UNIVERSITY OF IBADAN LIBRARY 
220
biology textbooks, the views expressed by authors, 
publishers, ministry officials, teachers and students 
were significantly different# However, teachers and 
authors expressed similar responses quite different from 
the other respondents#
Further inspection of the data, shows that the 
experimental groups subjects performed better than their 
control group counterparts with respect to challenging 
practical exercises#
These findings are a confirmation of earlier findings 
that there is a positive correlation between practical 
exercises and students performance in science (Hurd, 1969; 
Tamir, 1978; Ogunniyi, 1977)# The place of practical 
work in biology teaching is very crucial# According to 
Rai (1963), practical work provides first-hand experience 
and is far more important than lectures, discussion, 
questions and course content# It stimulates students' 
interest in science as well as develop in them the spirit 
of inquiry. To Ogunniyi (1986) a practical work is an 
indispensable aspect of science teaching# As the students 
perform experiments they improve their manipulative and 
observational skills# Ausubel (1968) and Hurd (1969)
UNIVERSITY OF IBADAN LIBRARY 
221
assert that in the classroom setting, the main goal of 
practical exercises is the provision of opportunities for 
students to investigate so as to develop essential practical 
skills®
As pointed out by Schwab (1962) and Ogunniyi (1983), 
practical exercises by their nature, provide students with 
opportunities to investigate and to study abstract 
concepts through concrete materials and consequently aid 
learning® Indeed, the overall teaching of science can not 
be broad-based without the inclusion of relevant practical 
exercises (Rai, 1963)® There are simple, specific, 
general or challenging practical exercises that can be 
employed in a biology lesson® The choice largely depends 
on the task in question, age and experience of the learner® 
The type and the timing of practical exercises need further 
studies® The data generated from such inquiries would 
aid teachers in selecting and sequencing practical 
exercises®in a meaningful way. Similarly, Examination 
bodies like the W.A.E.C. might find such data useful in 
their task of evaluating students® The present gambling 
procedure by teachers and examiners in the selection of 
practical exercises is unsatisfactory for the meaningful
UNIVERSITY OF IBADAN LIBRARY 
222
study of biology,,
Another area of interest in this study relates to 
the physical appearance of the textbooks involved in the 
study0 STAN Biology was found to contain the greatest 
varieties of cover and text colours, in addition to a 
wide variety of characters,,
Physical features are an often neglected attribute 
of most biology textbooks,, For example, it might be 
impossible to obtain the real materials or their models,,
In such a case, beautiful pictures and type sizes might 
be the closest resemblance of what is needed* There is, 
however, the need to empirically determine the merit of 
textbooks physical features to biology teaching and 
learning*
Readability of textual materials
One of the questions addressed in this study is 
whether or not there is a significant difference in the 
readability indices of the biology textbooks involved in 
this study* An examination of the result shows that there 
are significant differences among the textbooks with respect 
to readability indices* On the whole, only Mackean and
UNIVERSITY OF IBADAN LIBRARY 
223
STAN Biology can he regarded as easy textbooks for the 
subjects Involved in the study* Ewusie, Stone and 
Cozens need to be reviewed to meet the comprehension 
levels of the subjects involved in the study. It is worthy 
to bear in mind that English is a second language for the 
students. The easier a textbook is, the better for the 
students. The appauling state of English in our schools 
is common knowledge. Besides, most of the students rely 
almost completely on the textbooks for obtaining scientific 
information. Therefore, unless the language of a text­
book is easy enough, it becomes the very barrier to students 
understanding of science (Ogunniyi, 1986).
Various studies have established that readability 
indices is a measure of the comprehensibility of a 
textual material (Yoloye, 1975; Uche, 1979; Wahome 1979).
In line with the findings of Jegede (1982) and Okpalla 
(1982) on physics textbooks, this study shows that only 
Mackean and STAN Biology are adequate and easy enough to 
be understood by Form Four students - and by extension 
Form Five students (that is only students preparing for 
the WASC examination. All the textbooks by interpretation 
of the readability data (Wahome, 1979) are inadequate for
UNIVERSITY OF IBADAN LIBRARY 
224
Pofm Thbee studehts Who ate just beginning the study of 
biology. The irony of the situation is the fact that 
these books are supposed to be Used for Forms Three,
Four and Five students® This is why authors need to 
review science textbooks not jUst in terms of meeting 
examination requirements, but also taking care of the 
learners knowledge, needs, interests, grade and age. Of 
course, the implementation of the 6-3-3—4 programme would 
warrant the review of all the textbooks to meet the 
senior secondary school needs®
It should be pointed out here that readability values 
are not necessarily the only measure of textbooks adequacy. 
Earlier, we examined such things as$ questioning styles, 
technical terms, practical exercises, specimens, pictures/ 
diagrams, major themes and physical features of biology 
textbooks. All these are critical to the quality of any 
science textbook.
Generally, almost all readability formulae in use 
have been variously criticised by researchers. As alluded 
to earlier, Fleschfs (1948) readability formulae used in 
this study was seriously criticised by Dale-Chall (1948)
UNIVERSITY OF IBADAN LIBRARY 
225
as being very cumbersome to use* It wgs found desirable 
for this study because as Yoloye (1975) pointed out, it 
does not make use of difficult words as an index, and it 
is not culture-bound*
The easily identifiable limitations of readability 
formulae include their inadequacy as predictors of 
elements of comprehension such as graphs, characters of 
print and diagrams (Okpalla, 1982)* This has made it 
necessary for researchers to provide additional explana­
tion on the merit of reading materials for identified 
differences in students comprehension, abilities and 
reading efficiency* Research efforts should also be 
directed towards examining the relationship, if any, of 
students age, sex, socio-cultural background and previous 
experiences to their ability to comprehend classroom 
reading materials*
Conclusion
This investigation represents an extension of research 
on the relative effects of textual communicational strategies 
to learning* The focus has been on the role of textbooks 
in biology teaching and learning* The aim has been to 
identify the communicational strategies in four commonly
UNIVERSITY OF IBADAN LIBRARY 
226
used biology textbooks,, These strategies were consequently 
used in teaching selected topics in biology to Form Four 
studentso
In seeking an effective use of communicational 
strategies in biology teaching, the selected strategies 
were found to have produced better cognitive, affective 
and psychomotor performances in the students exposed 
to them*
It was also found that the textbooks used in the 
study had varying types of communicational strategies#
Of the seven major (madt-up of 32 subgroups) communicational 
strategies, the textbooks were isolated in terms of the 
strategies in which they excel# Since no one textbook 
had an overall advantage over the others, the findings of 
the study is in support of using as many textbooks as are 
available in biology teaching/learning, as this would 
provide teachers and students with greater variety of 
communicational strategies#
The variety in the viewpoints of the producers and 
consumers of biology textbooks also demonstrate the same 
point of providing teachers and students with wide variety 
of biology textbooks# In addition, the respondents*
UNIVERSITY OF IBADAN LIBRARY 
recognition of the vital role of communicational strategies 
in biology is sighificant*
This study seems to suggest that secondary school 
students exposed to a variety of communicational strategies 
will perform better than those not so exposed., Findings 
in the different states in the country would help to 
ascertain the merits or otherwise of the present study.
In addition, the present socio-economic realities of 
our time, demand that we should utilize the limited 
resources at our disposal for maximum benefit.. The 
present system in which all the schools in a state are 
made to use a single textbook in a subject area is grossly 
inadequate and unacceptable. This study has shown that 
efforts should be made to provide enough textbooks in 
our school libraries so that teachers and students can 
have the opportunity of the varying strategies offered in 
these textbooks. Community libraries for selected schools 
in contiguous localities grouped into units can be viable 
alternatives. In this way, the available scares resources 
can be made available to a greater number of learners.
From the foregoing, the following conclusion has been
UNIVERSITY OF IBADAN LIBRARY 
226
reached with respect to the relative effects of communica-
tional strategies in biology learning:
1. Mackean is the most adequate for contextual, factual, 
leading, probing and terminal questions.
2. For technical terms defined at first occurrence, 
Mackean is the most adequate.
3. STAN Biology is the most adequate textbook on local 
specimens.
4. Mackean is the most adequate for labelled diagrams/ 
pictures.
5. STAN Biology is recommended for teaching evolutionary, 
ecological, inquiry and traditional world-view themes.
60 For teaching challenging practical exercises, Stone 
and Cozens appears to be the best.
7. Students exposed to a variety of communicational 
strategies perform better than those not so exposed.
8. Authors and teachers appears to have similar views 
of the use of communicational strategies in biology 
textbooks.
9. With the exception of the use of challenging exercises, 
Mackean and STAN Biology seem to be the best texts 
among the popular biology textbooks available in
UNIVERSITY OF IBADAN LIBRARY 
229
Nigeria* The other texts require an urgent review.
It is hoped that the experiences gained in this 
study would dontribuke positively towards efforts aimed 
at finding ways and means of making science textbooks 
of better quality. A replication of this study with 
larger samples in the different states of Nigeria is 
recommended.
Implications
The overall poor performance of the control group in 
this study, has demonstrated the weakness of some teaching 
methods as they affect biology teaching and learning.
The often monotonous, unspecialised method of teaching 
in our schools has made the study of biology largely 
related and associated to only the passing of prescribed 
examination. This position is unacceptable, and the 
search for alternative methods is therefore crucial and 
necessary.
This study has been able to suggest more promising 
strategies of organising and executing biology lessons.
The selected communicational strategies used in the study 
have been shown to promote students cognitive, affective 
and psychomotor performances. The study also showed that
UNIVERSITY OF IBADAN LIBRARY 
230
the authors of the biology textbooks used in the study 
have recognised those strategies and have to some extent 
incorporated them in their books0 Furthermore, evidence 
has been provided to show that producers and consumers 
of biology textbooks recognise and appreciate the signifi­
cance of communicational strategies in biology textbooks 
and their consequent merits in biology teaching and 
learning* Although the various groups do not always 
agree on these strategies, this is how it should be* 
Varieties of textbooks on a given subject can be used to 
advantage, since no one text is good in every area of 
communicational strategies*
The advantages of this finding centre on two issued* 
First, is the relevance to teaching and learning of biology* 
For sometime, readability indices have been regarded as 
the central issue in students comprehension of textual 
materials* The findings in this study have shown that 
although readability is important, it is has been considered 
only in its narrower meaning* In other words, readability 
is much more complex than the written materials per se*
It also entails the context in which the written materials 
as well as the pictures, diagrams, technical terms, themes 
and other communicational strategies fit together to
UNIVERSITY OF IBADAN LIBRARY 
231
engender comprehension. The communicational strategies 
selected for this study has been found to contribute 
quite significantly to the effective comprehension of 
biology textual materials.
Second, is the identification of the merits or other­
wise of communicational strategies in the cognitive, 
affective and psychomotor performance of students 
in biology. In addition to isolating specific strategies 
for biology teaching and learning, the findings in the 
study have shown that there are communicational strategies 
requiring further differentiation, specification and 
experimentation in the teaching and learning of the 
subject.
The crucial issue involved is that teachers of biology 
should be familiar with the textbooks available in the 
market. They should be able to recognise and be aware of 
the merits and demerits of these textbooks in terms of 
communicational strategies they use in the presentation of 
learning materials.
Another implication of the study, is that while it is 
not possible nor desirable to purchase all the books 
available on a subject, the teachers and school authorities
UNIVERSITY OF IBADAN LIBRARY 
232
should ensure that the school library have most of the 
textbooks needed for reference purposes* The advantage 
of this is that studehts can avail themselves with the 
various advantages that such a variety can produce* With 
a fairly well-equipped library containing several biology 
textbooks with a variety of communicational styles of 
presentation, the teacheris are left with the responsibility 
of distinguishing, isolating and Utilizing the best 
communicational strategies in the classroom setting*
This will consequently make teaching interesting, meaning­
ful as well as enhance the students performance in biology, 
in addition to providing teachers with challenging tasks 
for the overall benefit of the teaching—learning objectives* 
Recommendations
In the light of the findings in this study, the 
following recommendations have been made for proper 
consideration*
(a) Biology Teachers? In order to promote cognitive, 
affective and psychomotor performance of students, 
biology teaching should involve;
(i) An identification of the merits of biology 
textbooks in relation to the communicatic»al strategies
UNIVERSITY OF IBADAN LIBRARY 
233
they contain, and sieve out how these can be effectively 
used ih promoting leairnihg* It should be noted that while 
the Students can be triade to buy the best book (as deter­
mined by the teachers and ministry officials) the teachers 
and the school library should ensure that other books in 
the same subject area are available for reference purposes* 
The teacher as a facilitator of learning should from time 
to time refer the students to specific textbooks depending 
on the desired strategies*
(ii) In preparing the lesson note the biology teacher 
should bear in mind the communicational strategies that 
he has isolated, and which he considers to be best suited 
for the learning tasks* Each strategy should be well 
listed out, with specific objective and time interval 
envisaged* With practice, the strategies can be used as 
and when necessary in the teaching phase. This no doubt 
calls for adequate planning and preparation on the part 
of the teachers* The preparation will necessarily 
include in addition to getting a specialised note of 
lesson, adequate reference books, diagrams and specimens 
that will be needed during teaching. Teacher training 
Institutions can be of great help in equipping teachers
UNIVERSITY OF IBADAN LIBRARY 
234
with the necessary skills needed for this tasko
(b) Authors: To promote the teaching and learning of
biology, authors of biology textbooks should be conscious 
of the increasing role of textbooks in biology,, In 
preparing and writing textbooks (or revised editions) , 
they should endeavour to use varying communicational 
strategies to convey meaning of difficult concepts, and 
aid comprehension of students.
Since there are numerous communicational strategies, 
authors should select and use those ones that have been 
identified by research to be valuable to students 
comprehension and interest. The objective should not 
only be to provide books for examination purposes, but 
that book which will promote a scientific literate citizenry.
(c) Publishers: As the producers of textbooks, publishers
should be aware of the significance of textbooks in science. 
Although publishers' consideration is strictly commercial, 
they have a moral obligation to ensure that the textbooks 
they produce can contribute significantly to the cognitive, 
affective and psychomotor performance of the learners.
Consequently, in the conceptualisation and writing 
periods, publishers should identify suitable communicational
UNIVERSITY OF IBADAN LIBRARY 
235
strategies, discuss with their authors and delibrately 
ensure that the strategies are incorporated into the 
textbookso In this way, the publishers would be 
contributing their quota to the development of biology 
teaching and learning, A constant review of their text­
books is recommended,
(d) Ministry Officials: Prevailing political and
economic realities, have made the role of Ministry of 
Education officials crucial in the teaching and learning 
of biology. Today, the officials often times single- 
handedly determine the books to be used in the schools 
without reference to the teachers who would eventually 
use them. The aim here is not to critize the system, 
but their function underscores their importance in the 
school system. It seems that they can not play a meaning­
ful role that they are expected to play unless they are 
well acquainted with the criteria that determine the 
quality of a given text. It is recommended that workshops 
organised by ministry officials should place adequate 
emphasis on the selections,identification and utilization 
of science textbooks.
Furthermore, this study has shown the need to have
UNIVERSITY OF IBADAN LIBRARY 
236
a committee comprising Ministry officials, authors, teachers 
and students who would be involved in textbooks selection.
The advantage of this, is that these individuals with varied 
experiences, knowledge, training and expectations are better 
placed to select the textbooks that are interesting and 
appropriate for students learning.
(e) Ministry of Education; to maximise resources, the ministry 
of education need to consider the following recommendations;
(i) pre-service, in-service and workshop sessions should be 
designed for teacher trainees, new and serving teacher trainers 
to develop their skills in identifying the merits, and demerits of 
strategies in textual materils.
(ii) District or community libraries are recommended to supplement 
or serve as alternatives as it is not uncommon to find some 
schools without a library.
(iii) All those involved in the sacred duty of training the young 
(publishers, officials, authors and teachers) shsuld have a regula 
forum (e.g. seminars and workshops) for exchange of ideas on 
biology textbooks in classroom teaching and learring.
(f) F^r Further Research: since this study is explanatory,
UNIVERSITY OF IBADAN LIBRARY 
237
it is necessary that further research be carried out in 
the area to explore the following:
(i) What other strategies other than those identified 
in this study can promote cognitive, affective and 
psychomotor performances students in biology?
Cii) What other criteria (apart from those identified in 
this study) are necessary in determining how one or more 
communicational strategies should be used in a science 
lesson?
(iii) What is the nature of communicational strategies used 
in other biology textbooks as well as textbooks in Physics, 
Chemistry, Integrated Science and Agricultural Science?
(iv) What are the effects of selected communicational 
strategies on students’ learning in Integrated Science, 
Physics, Chemistry and Agricultural Science?
(v) In the spirit of the 6-3-3—4 system, how can communica­
tional strategies be effectively utilized to make text­
books adequate for third, fourth and fifth form students?
UNIVERSITY OF IBADAN LIBRARY 
238
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UNIVERSITY OF IBADAN LIBRARY 
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APPENDIX 1
fcfiAbABlLlTY INDEX
(R. I-)
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READABILITY DETERMINATION
The readability of the four textbooks used in the 
study were determined using Flesch*s (1948) readability 
formulae* The books examined were Mackean, Stone and Cozen, 
Ewusie and STAN Biology*
PURPOSE
The purpose of the readability determination was to 
determine the difficulty levels of the textbooks and
deteirfaihe their suitability fot the comprehension level of
!
the students*
INSTRUMENT
Flesch’s (1948) readability formulae and its interpre­
tation data relative to Nigerian schools was used for the 
study* The formula has been used extensively by Major and 
Collette (1961), Marshall (1962), Wahome (1979) Jegede (1982) 
and Okpalla (1982)* Although the readability formulae can 
not measure elements such as graphs and diagrams which are 
capable of influencing the reading comprehension of Biology 
textbooks, it has a number of advantages. Itls suitable 
for this study for the following reasons:
(a) It does not employ word list.
UNIVERSITY OF IBADAN LIBRARY 
266
Cb) It utilizes measurement of sentence length and 
syllable counto
(c) It utilizes measurement of sentence complexity
(count of word length and number of syllable per 
hundred words), is a reliable measure of abstra- 
tion (Marshall* 1962)o
PROCEDURE
The procedure adopted ih the readability determination 
included}
10 The textbooks to be used are the four used in the 
study.
2. Selection of a paragraph each from every sampled 
page (every tenth page, as in the textbook 
analysis).
3. Eaata paragraph should have about 100 words.
For each sampled paragraph, the following data will be 
collected;
(i) Number of words in the sample.
(ii) Number of syllable in the sample.
(iii) Number of sentences in the sample.
(iv) Average sentence length (ASL)0
ef ccn z
(v) . ' 1 ; =■ i ■ r. . C
UNIVERSITY OF IBADAN LIBRARY 
267
ASL «= Number of words in a sample
Number of sentences in a sample
(v) Word length (Wl ) *= Ntxmber' of syllables in 100 words..
From the above data, the Flesch's readability score (RS) 
is given as:
RS = 206*835 - 0.846 WL - lo015 ASL
This was done for all pages sampled. The average is 
the readability score of the book.
Flesh's interpretation of the readability data relative 
to Nigerian schools (Wahome* 1979) was used in interpreting 
the readability scores computed for the four books*
UNIVERSITY OF IBADAN LIBRARY 
268
Flesch*s Interpretation of Readability 
Data Relative to Nigerian Schools
Readability
Score 70-79 60-69 50-59 40-49
h
Average
Sentence 14 17 21 25
Length
Syllables
Per 139 147 155 155
100 Words
Description 
of styles Easy Fairly Standard Fairly
(4th year easy Difficult
students)
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269
APPENDIX 2
Communicational Strategies Survey
(CSS)
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270
Communicational Strategies Survey 
(CSS)
Dear Respondents,
This survey is to seek your candid opinion on the status 
and your preference for the strategies examined in this 
survey#
The survey is not a test and information shall be 
treated in confidence#
Name:
Sex:
Occupation:
The questions that follow, relate to various communica- 
tional strategies that can be found in a Biology textbook# 
You are to rate these strategies from 1 to 5 by ticking
j
in the column providedt if you prefer a Strategy best* yoU 
rate it as I by ticking the column for 5, and the least 
preferred is rated 1 by ticking 1 in the column#
Please express your candid preference for any of the 
strategies#
Key for Rating 
5 = Very Essential
4 Essential
UNIVERSITY OF IBADAN LIBRARY 
271
3 = Sometimes essential
2 = Hardly essential
1 = Not essential
Now, answer the questions
Use information below to answer ques«-i 
tion 1 — 4;
Biology textbooks should use questions 
that are:
10 Factual (recall o£ ^acts)...
20 Rhetorical (Ifeguilre no
answer) ..... .
3» Leading (directed to a 
later answer)
4„ Probing (require evaluation
and giving personal opinions)*, 
For questions 5 — 8 use the 
following information;
The questions in a Biology textbook
S h O U l d  b e *  o o o e o o o o o e o e o o o o o o o o
5
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5. Introductory (at the beginning 
to arouse interest) .......
6* Contextual (within the
meaning of a subject matter)*.* 
7« Terminal (at the end to
evaluate understanding) . ..*
80 Captional (used in reference 
to a heading, table, graph, 
illustration) ...............
Answer questions 9—12 using the state­
ment below:
Technical terms used in a Biology 
textbook should be...............
9* Defined when used............
10* Earlier defined (before 
in introducing the term)..... ....
11. Later defined............ .
12. Should be undefined............
The statement below is for questions
13 - 15;
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When specimens are mentioned or
ror pi. uotical <ay o cs<5 ̂ 
tbfe Sfc>ebimens should be*..... .
13. Lobal specimens»...«..ba...
14. Foreign specimens..... t. a«.«
IB« Reserved specimens. . ....<>.
Answer questions 16-25 using the 
statementj
A good biology textbooks should
i
have..oo.o.e.
16a Pictures only.ooooooo.ooo«.o
17.  Piagrams only.o©.o..ooo.o o oo
18. Both pictures and diagrams...
19. Good descriptions only......
20o Pictures and diagrams should
be labelled.o o o o o o o o . e o o o .
21. Pictures and diagrams should 
not lae 1 abe11ed. . o o . a o . . . o e
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5 4 3 2 1
22# Pictures and diagrams 
should be sometimes 
labelled* c.**.***....****
23# Pictures and diagrams should 
be in colour^*& *
24# The pictures and diagrams 
should be in Mack and
V/hlle* o o o o o o o o o o o o o o o o o o o o
25# The pictures and diagrams err 
can be shaded**0 0 0 0 **0 * * 0 0 0 0  
For questions 26 — 29, use the 
following statement* *0 0 0 *0 0 0 0 0 * 0 0 0 0 0  
In a biology textbook, the 
practical exercise suggested 
should be*0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 *0 * 0 0  
260 Simple (casual observation)** 
27* Specific (individual 
1 aboratory work
28. General (student/cr group
PrOjeCt) * 00*00*0000000000*000
1
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290 Challenging (student/group 
or teacher demonstrate 
specialised knowledge or
Skill) • o o o e o o o o o e o e e o a o o  o o o
Use the statement below for questions
30-36.
A good Biology textbook should 
fettiphasize itldjor thetnes of 
importance to the student and 
the society.
Important themes should include: 
3©0 Evolution (development trends 
in Biology systems)........
310 Ecology (inter-relationship
of organisms and environment) 
32© Economic importance ( • .' ,;1 • .• 
(benefits to man),.,.....,
33. History (stories of
discovery)„eoooooooooo
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340 Inquiry (finding out more 
clbOUt things) © o o e o e o o e o o  
35© Knowledge (factual present­
ation of topics)© o o o o o o o o o  
36© Traditional world-view 
(views influenced by 
cultural beliefs)« *©»b*© ©. 
The following statement is for 
questions 37—39©
The cover of a Biology text- 
book should beooooooooooo.ooooo 
37© Be of plain cover© o c©© ©© © ©. © 
380 Cover should have coloured
pictures and diagrams,....©. 
39© The cover should be in black 
and white illustrations©©©s© 
Questions 40—43 concern what should be 
the qualities in the main text of a 
Biology textbook©
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40* The main text should have 
colours for distinguising 
sections,.
410 The characters in the main 
text should be in black 
Only,40090ft.«0eci.db000e0
42o The characters in the main 
text should be in different 
sizes (as in subsections).,.
430 The characters should all
be in the same size.0 0 0 ,0 0 0 ,
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APPENDIX 3
Text—Books Analysis Index
(TEA)
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TEXTBOOKS ANALYSIS (TPA) INDEX
The four textbooks (Most popular — Balogun 1979) 
analysed were:
1. Mackean, D.G. — introduction to Biology.
West African Edition, Heinemann Educational Books 
(Nig.) Ltd., 1982.
2. fcwUsie, J.Y* - Tropical biology for *0* Level and 
School Certificate, Africah University Press In 
Association with Harrap, London 1982.
3* Slones, R.Hj, and Cozend, A.B. New Biology for 
West African Schools. Longman Group Ltd., London 
1982.
4. STaN Biology - Addison Wesley.
London, 1983.
The textbooks were analysed using a modified version of 
communicational strategies used by Ogunniyi (1982).
For the analysis, sample pages were taken for all the 
four books.
The analysis involved a slightly modified version of 
Ogunniyi’s (1982) communicational strategies in the following
areas:
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1„ Status of pictures and diagrams
20 Nature of practical suggestions,,
3» Physical characteristics of the textbooks,,
40 Type- and position of questions.
50 Occurrence of major themes.
6* Technical terms,,
70 Specimens 
1. Questioning Styles:
(a) Type of questions with respect to whether they 
aret
•u Factual
— Rhetorical
— Leading
— Probing
(b) Position of questions with respect to:
— Introductory
— Contextual
— Terminal 
— — Captional
20 Terms:
— Terms defined as used
Earlier defined
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— Later defined
— Undefined 
30 Specimens;
— Local specimens
• 'on— local specimens 
4» Status of major themesi
— Evolution
— Ecology
L Edohomic impotence
it irî liiiry
— History
— Knowledge
— Traditional world-view (superstition)
5P Status of pictures and diagrams:
— Number of pictures
— Number of diagrams
— Number of labelled and unlabelled pictures
and diagrams.
— Number of colours used for pictures and 
diagramse
6® Nature of practical suggestions:
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— Simple
— Specific 
General 
Challenging
7® Physical characteristics of textbooks:
— Number of colours on the cover
— Number of colours in the text
— Number of characters used in the text (type
sizes)o
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APPENDIX 4
Subjects Selection Test 
(S.S.T.)
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A. The following are test items based on what you have 
done previously in Biology*
B* You aire expected to read through very carefully and
choose from among the alternatives by circling with a 
pencil or biro the letter A, B, C, D or E corresponding 
to the correct or most correct answer*
C, If you do not know an answer to a question, move to 
the next*
I4 Air contaihs about (78%) seventy-eight percent of 
a gas called*
(a) Nitrogen 
(t>) Wateir
(c) Oetygen
(d) Hydrogen
(e) None of the above
2* When an amount of water will not dissolve any 
more salt, the solution is said to be*
(a) Saturated
(b) Unsaturated
(c) Hydrated
(d) Super—hydrated
(e) None of the above
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3. When a candle is burning, two chemical compounds are 
formed dalled*
(a) Carbodioxide and water
(b) Oxygen and carbon 
Cd) Oxygen and hitrogen
(d) Oxygen and hydrogen
(e) Hydrogen and water
40 Water enters plant root hairs by a physical process 
called?
(a) Diffuiî ort
(b) OsmosiH
(c) Passage
(d) Movement
(a) Assimilation 
50 A molecule of water contains:
(a) One atom of oxygen and two atoms of hydrogens
(•.) *u<
(b) Two molecules of oxygen
(c) Two molecules of hydrogen
(d) Two atoms of oxygen and one atom of hydrogen*
(e) None of the above
6» Water will boil at the temperature of:
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(a) 100°C
(b) 0°C
(c) 0°F
(d) 100°F
(e) 120 °C
7. The mass of an object is the quantity of
(a) MatteJr in it
(b) Weight of it 
(d) Volunie of it
(d) Height of it
(e) None of the above
8. The relative density of a substance is the ratio of 
the mass of the substance tot
(a) Mass of equal volume of water
(b) Weight of equal volume of water
(c) Density of water
(d) Weight of substance
(e) None of the above
9» The weight of a floating object is equal to the •».»« 
of fluid displaced,,
(a) Weight 
<b) Volume
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(c) Density
(d) Mass
(e) None of the above
10* All acids turn bltie litmus paper to
(a) Red 
'(b) fc>ink
<fcc) BlUe
!
(d) Colourless
(e) No change
110 The chemical name for quickline is
(a) Caiciium okide
(b) Calcium dioxide
(c) Calcium oxygen
(d) Sodium dioxide
(e) Sodium oxide
12o When carbondioxide dissolves in water, it forms a weak
(a) Acid
(b) Base 
(S) Solvent
(d) Mixture
(e) Alkali 
13® Chlorine is a
(a) Gas
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(b) Liquid
(c) So'.Old
(d) Solution
(e) Mixture
When ibdinfe Is; put into starchuthepcdlouco^otris c i
(a) Blue black
(b) Black
Cc) Blue
(d) Yellow
(e) White
The 'green colour of leaves is called
(a) Chlorophyll
(b) Green
(c) Iodine
(d) Starch
(e) None of the above
When two tuning-forks are beaten and brought near
each other there is
(a) Resonance
(b) Equilibrum
(c) Touching
(d) Sound
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(e) Noise
If, When dilute acids are added to carbonates, they give
(a) Carbon dioxide
(b) Water
(c) Oxygen
(d) Hydrogen
(e) Chlorine
18e Lime-water is a saturated solution of
(a) Calcium hydroxide
(b) Calcium oxide
(c) Lime
(d) Carbon dioxide
(e) Carbon
19<* A type of water which does not readily form lather with 
soap is called:
(a) Hard—water
(b) Dry water
(c) Soft water
(d) Non-lathering
(e) Saturated water
20o Common salt will met at a temperature of:
(a) 850°C
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(b) 1 0 0  °c
(c) 850°F
(d) 100°F
(e) 112°F
21. When sodium chloride is added to hydrogen sulphate the 
result is the formation of
(a) Hydrogen and sulphate
(b) Hydrogen chloride and sodium sulphate
(c) Chloride and sodiufco sulphate
(d) Sulphate
(e) Chloride
22. Hydrogen chloride is
(a) Acidic
(b) Basic
(c) Alkali
(d) Amphoteric
(e) None of the above.
23. When a sound is reflected it is called an 
Ca) Echo
(b) Sound
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(c) Noise
(d) Vibration
(e) Boumerang
24. The speed of sound in dry air at 0°C is about
(a) 500 meters per second
(b) 1 meter perssecond
(c) 1 kilometer per second
(d) 10 meters per second
Ce) 1000 kilometers per second
25. The reproductive part of a plant is the
(a) Flower
(b) Stertt
(b) Root
(d) Leave
(e) Nodes
26. An instrument used for measuring temperature is called a
(a) Thermometer
(b) Guage
(c) Meter
(d) Voltmeter
(e) Ammeter
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27* Solid, liquid and gas are classified as
(a) Matter
(b) Gas
(c) Solid
(d) Liquid
(e) Solution
28* An animal which can live on land and water is calj-fed an
(a) Amphibian
(b) Fish
(c) Animal 
Cd) Monkey
(e) Water-animal
29# Lining things are also called
(a) Organisms
(b) Solid
(c) Liquid
(d) Gas
(e) None of the above
30* A type of energy is called
(a) Light energy
(b) Gas energy
(c) Solid nergy
( i r- •
(
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(d) Liquid energy
(e) Molten energy
31* A power station in Nigeria which converts Kinetics 
energy into electrical energy is the
(a) Kainji Dam
(b) School plant
(c) Electricity plant
(d) Plants
(e) Animals
32, Energy on earth comes from the
(a) Sun
(b) Moon
(c) Stars
(d) God
(e) Jupiter
33, The process in which a substance moves through into 
another is called
(a) Diffusion
(b) Movement
(c) Displacement
(d) Coiling
(e) Respiration
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340 Scientists call a statement which has not be tested as
(a) Hypothesis 
Cb) Formulae
(c) Observation
(d) Experiments
(e) Tests
35, When a solute is dissolved in a solvent the result is 
the formation of a
(a) Solution
(b) Liquid
(c) Solid
(d) Gas
(e) Acid
36, When substances burn in oxygen, they combine with it 
to form
(a) Oxides
(b) Hydrides
(c) Carbonates
(d) Water
(e) Solution
37, Animals with backbone are called
(a) Vertebrates
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(b) Invertegrates
(c) Amphibians
(d) Solids
(e) Water-birds
38. Flesh—eating animals are called
(a) Carnivores
(b) Herbivores
(c) Plant eater
(d) Scavengers
Ce) All of the abovet,
39. Fertilized ovules of plants result into
(a) Seeds
(b) Leaves
(c) Roots
(d) Stem
(e) Chlorophyll
40. Substances which do not conduct electricity are called
(a) Insulators
(b) Conductors
(c) Salts
(d) Solids
(e) Metals
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41« Sound travel as a
(a) Wave
(b) Noise
(c) Vibrations
(d) Solid
(e) Gas
42* For healthy growth human beings need a
(a) Balanced diet
(b) Vitamins only
(c) Minerals only
(d) Water
(e) Salt
430 Deposited rocks under water beds are called
(a) Sedimentary rocks
(b) Igneous rock
(c) Metamorphic rocks
(d) Simple rocks 
Ce) Complex rocks
440 The earth rotates about an
(a) Axis
(b) Plane
(c) Circle
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Cd) Horizontally
(e) Vertically
45» When the earth rotates round the sun it results into 
the formation of
(a) Seasons
(b) Climate 
Cc) Weather
(d) Rain
(e) Snow
46« A system of bones is called a
(a) Skeleton
(b) E*emur 
Cc) Bones
(d) Cartilage
(e) Humerous
470 Metals are generally regarded as good conductors of
(a) Electricity
(b) Gas
(c) Light
(d) Solids
(e) Water
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48„ All living things are made up of simple units called
(a) Cells
(b) Organs
(c) Systems
(d) Tissue
(e) Cytoplasm
49. A stored energy in a substance is called
(a) Potential energy
(b) Light energy
(e), Sublimation energy
(d) Solid energy
(e) Liqhid ehergy
50. The removal of liquid waste from the body is called
(a) Excretion
(b) Digestion
(c) Assimilation
(d) Polution
(e) Urinating
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EXPERIMENTAL STUDY
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TRE21A TMENT.  -CV ONOD IÌ-’TUIITQIN'S  O"V
Treatment was carried out on thè experimental and 
control groupso Before and after thè treatment thè following 
Instruments were administered,
lo Students Attitudinal Test (SATT)
2o Students Achievement Test (SAT)
3» Students Psychomotor Test (SPT)
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COMMUNICATIONAL STRATEGIES FOR THE . 
STUDY
The selected communicational strategies used in thè 
study included; questioning styles, technical terms, ; a 
specimen, status of diagrams and pictures, major themes 
and practical exercises.
The treatment conditions included thè following 
Communicational strategies;
1» QUESTIONING STYLES
(a) Leadinq and probinq questions
' i • *' 1
Thefee hdve been empetically found to be of 
higher order questions that stimulate inquiry 
behaviours than other types of questions 
(Stevens, 1912, Gali, 1970; Rave, 1974; 
Ogunniyi, 1981} 1983 and Carrick, 1982)a
(b) Cpntextual Questions
They have been determined emperically as very 
valuable (Ogunniyi, 1981; Carrick, 1982)*
2® TERMS
Defined terms (at first occurrence)
As determined by (Evans, 1976) thè terms defined 
at first occurrence facilitate reading and
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304
comprehersion.
3C SPECIMEN
Locai Specimens
Locai specimens are valuable to teaching and 
learning since they are readily available in thè i
teaching environment, and are familiar to thè 
students (Ogunniyi, 1982).
4. PICTURES AND DIAGRAMS
Labelled diaqrams and pictures 
These are indispensable mèmory aids unlike thè 
unlàbelled diagrams that have little use td thè 
reader. (Ogunniyi, 1982).
5* MAJOR THEMES
Inauiry Method
The current emphasize in science education is thè 
presentation of school science as a form of inquiry 
(Ogunniyi, 1982; Schweb, 1962).
6. PRACTICAL EXERCISES
Challenqinq exercises
Practical exercises provide students with unique 
opportunities to study abstract concepts and 
generalisations through thè medium of reai materials.
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Kerr (19C3) and Oguniiiiyi C1977) contend that 
challenging exercises are suitable for upper 
classes, while simple and specific exercises 
are suitable for lower forms»
I
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APPENDIX 5
Students Attitudinal Test (SATT)
The students attitudinal test was designed to see how thè 
communicational strategies used during treatment affected thè
attitudes of thè students to Biology.» 
nateqorisation of items in Attitudinal Test 
_____into communicational strategies_______
0' . . ' . ....
Items
(Questions) Communicational strategies
1 - 3 Questioning styles
Technical Terms
7 - 9 Specimens
10 - 12 Status of pictures and diagrams
13 - 15 Major Themes
!6©ndl7 practical Exercises
physical attributes of textbooks
i
<T>
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or-ot
307
Students Attitudinal Test (SATT)
This questionnaire is concerned about your interest 
in Biology0 Please fili in thè information required as 
honestly as possible»
This is not an examination»
Names
Schools
Sex:
Now respond to thè questions. You are to indicate in 
thè column provided if you agree or disagree with thè 
statement*
Agree = 2
Disagree = 1
Agree Disagree
2 1
1. Biology is interesting when 
leading questions are used (This 
is a question directing to thè 
answer)»
2c X like Biology when probing 
questions are used (iee„ questions 
requirìng criticai consideration of
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308
personal opinion)
30 I find Biology interesting when 
confcextual (i«e« thè questions 
are asked within thè textual 
material)•
4« I tend to forget Biology terms 
very easily»
50 Biology terms make uninteresting.
60 I like Biology when thè terms are 
defined when used»
*70 Biology is interesting when 
locai materials are used.
80 The long names of biological
specimens make thè subject boring 
and uhintetesting»
9, I hate Biology because it deals 
with messy and smelly preserved 
materials»
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Agree Disagree
2 1
10 I like Biology because of thè 
good diagrar.is and pictures.
11. I like Biology because thè diagrams 
and pictures are usually well 
labelled.
12. I like Biology when thè diagrams 
and pictures are in different 
colours.
13. Biology is iritereSting to me 
when thè inquiry method (finding 
out more about things) is used.
14. The theory of evolution (structures 
and/or developmental from a 
common orlgin) trends in Biology 
systems contradicts my faith in 
God as thè Creator of all things| 
hence I do not like to study 
Biology.
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15. Biology is interesting when thè 
ideas agree vxth those of my 
cultural beliefs.
16. Biology is interesting because 
thè practical exercises are 
usually challenging i.e. require 
team work.
I7w 1I do not like Biology because thè 
practical exercises exposes one to 
danger.
18. I like Bi.-logy because thè Cover 
of thè textbooks are coloured. 
19. Biology ià hot ihteresting to me 
because thè coloured words used 
in thè textbooks help me to 
remember thè terms.
20. Biology is very boring to me 
because thè words in thè textbooks 
are in different sizes.
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311
APPENDIX 6
jv-óents Achjevement Test (SAT)
The SAT was designed to see how thè strategies used 
t^ring treatment affected thè students cognitive performance 
in Biolagy.
Categorisation of SAT items into 
_____Ctmmunicationa1 strategies
[i'Qteumess tione) Communicational strategies
1 - 5 Leading questions
6'-10 probing questions
11 - 15 Contextual questions
I 16 - 20 Defined technical terms
21 - 25 Locai specimens
26 - 30 Labelled diagrams and pictures
31 - 35 inquiry method
36 - 40 Challending practical exercises
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Students Achievement Test SAT)
Dear Students,
Please answer thè questiona honestly and candidly*
Xf you do not know thè answer to a question, do not guess, 
leave thè question and go to thè next one,
This is NOT an examination*
Please provide thè following information:
Nartìe:
School:
Class:
Sexs
You are to spend one hour on this exercise, Each 
question has four options of answers, you are to indicate 
by cirdiing thè dnsWer that you think is thè fflosfc dtìèc}uated 
1« When an organism needs only inorganic food to synthesise 
complex organic molecules, it is eaid to exhibito*®.
Aa Autotropic nutrition
B. Saprophytic nutrition
C, Parasitic nutrition
Do General nutrition
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20 Organisms feeding on organic food substances, exhibit 
thè phonemenon of ......
A» Heterotropism 
B» Autotropism 
C0 Saprophytism
D. Parasitism
3* Inadequate supply of iron in food can result in a 
deficiency called ......
A, Anaemia
B, Goitre
C0 Blindness
Dò L. !oss of movement
4» Although trace elements (Zinc, Copper and Manganese) 
are qooc. foi: healthy girowth in {slantd* tHey are 
required in .....
A. Minute quantities
B, Large quantities 
C0 Only at night
D. During thè day
5, The gut of carnivores are shorter than herbivores 
because ......
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A0 Carnivores food is largely protein which is easy 
to digesto
B, Carnivores food is largely protein which can not 
be easily disgested*
C0 Herbivores feed on animals*
D0 Canivores feed mostly on plantse
6. Why do you think mammals have to store glycogen?
A, So that it can be hydrolysed back to glucose when 
needed»
B* So that it can be condensed back to glucose when
neededo
Ce So that it can be stored away.
D0 So that thè Mammals can feed only on plants»
7. What do you expect to happen if thè peristalis mbVtemeht 
in thè stilali ihtestihe ife disti*upted?
A, Movement of bolus of food will stop
B, Movement of bolus of food will be hastened 
e» The small intestine will burst
D0 Food will pass to thè large intestineo 
8C Why is thè enamel of thè human tooth very hard?
A, To prevent early wearing away»
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Be So that it could be used to crack hard food 
substances.
C, To keep thè Shape of thè teeth.
D0 For protection against dangerous animals.
9. In carnivores, thè temporal muscles are huge, but 
small in herbivores, why to you think there's thè 
difference?
A„ To allow for shearing action of carnassial teeth 
in carnivores and for only raising thè lower jaw 
in herbivores»
B. To oive a greater fórce to thè carnivores against
attackso
C„ To allow thè carnivores to open theib moutH larger 
t’ia.. in herbivores.
D* To allow thè herbivobes ehoUgh roòi'n to graze thè 
fieldo
10» In three test-tubes A, B and C, a cube of cooked egg
white was put„ Into A, sodium carbonate was added, in 
B distil water and into C hydrochloric acid was added. 
To thè three tubes, pepsin was then added. After 
24 hoursj thè cube in C when put in a warm place was
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totally digested, What can you say of A, B and C if 
nothing happens to B and C,
A0 Pepsin requires acid conditions to digest cooked 
albumen,
Q, Pepsin is active in cojd water
Cc Pepsin is active in sodium carbonate
D0 Pepsin is active in distil water when kept in a
warm place0
11, In thè school fariti* an organism like muàhrooms were
found oh dead materiàls* • These mushroorrts can be said 
to exhìbifcj
A, B.eterotrophism
B0 Autròtrophism
e» Sa* oophyism
D .  NcfJiì o f  t h è  a b o v e
12o Since plants can not move, a student set out to analyse 
their source of energy. In his finding, he found out 
that when sunlight was present, there was presence of 
starch in thè leaves. By his finding, thè plants 
source of energy is 
A* Sunlight
B, Minerals
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C. Vitamins
D. Respiration
13. In a West African town, a weak man with poor teeth
was asked to be taking food enriched with milk, cheese 
and bread. This it is to prevent .....
A. Brittle bones and teeth
B. Goitre
C. Blindness
D. Bow legsé
14. Why are hydrolysed units of food substances sometimes 
condensed in thè human body?
A. When food needs are to be stored
B. When food needs are to be used
c. When food is enough
Dii When food needs are inadequate
15. In ari fertfcerìrtlent on digestion, a student discovèred 
that thè colon does not contain digestive enzymes.
He concluded that thè reason is likely to be ..... .
A. Because all thè food substances have been acted 
upon, digested and assimilated in thè earlier 
digestive System.
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B. Because thè colon is short.
C. Because thè colon is before thè stomach and
intestine
D. Because thè cells in thè colon are dead.
16. Organic compounds are defined as ....
A. Complex, carbon - containing compounds
B. Complex polysaccharides
C. Complex carbon and hydrogen compounds
D. Complex nitrogen compounds.
17c The deficiency of iodine present in sea foods and 
table salts results in ......
A* Gaitre
B. Blintìness
C. Brittle hones
D. Bow legs.
18. An aggregation of monosaccharides are called .....
A. Polysaccharides
B. Disaccharides
C. Proteoses
D. Glucose
19. The smallest unit of Proteoses is called .....
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A, Amino acid 
Be Glucose 
Cc Sucrose 
D0 Fatty acids
The hepatic portai vein in thè villi carry blood to 
thè
A0 Liver 
B* Kidney 
C 0 Stomach 
Dé Small intestine
A livinn organism that is found in Nigeria exhibiting
holophytàc nutrìtion is
A, Hibiscus flower
B* Amoeba
Ci Mari
D, Rabbit
An organism that is found in thè bush in Nigeria and 
feeds on organic material is thè 
A. Rabbit 
B0 Palm tree
C» Coconut tree 
D. All of thè above
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23» To prevent a young Nigerian child from anaemia, he 
should be fed regularly on ......
A0 Liver and eggs
B. Meat and eggs
c. V- jgetables and liver
D. Beans and eggs.
24. In Nigeria, a common ectoparasite is ......
9 A. Mosquitoes
B. Flies
c. Cockroach
D. All thè above.
i ,
25. A Nigerian food with plenty of proteiri is thè ....
A. BeartS
B è Vams
c. Cassava
D. Vegetables.
26 «■» 30 and 31 — 35
Fig• 1 attached is to be used in answering questions
26 - 30.
Fig• 2 should be used in answering question 31 — 35.
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Questions 26 — 30 O ’se Figure 1)
26« A is thè outer layer in thè organ shown, what should 
be its nature?
Ac Thin for easy absorption 
B„ Thick for easy absorption
C„ Thick for protection
D* Thick for peristalsis
270 What type of food materials are carried in 3?
A. Water soluble 
B0 Fat soluble
C0 Protein soluble 
De PolysaccharieS
i , j ; I
28b What typè of fddtì subî thrtCes are Càrried in C?
Ae Fatty substances
B, Protein substances
C„ Glucose
D# Proteoses
29« Why is D called fchehepatic portai vein?
A, It carries blood to thè liver
B0 It carries blood to thè stomach
C* It carries blood to thè intestine
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D» It carries blood to thè bile.
30o E is a blood vessel to thè thoracic duct, where is It 
lccated?
A„ Main vein of thè left arm 
B„ Main artery of thè left arm 
C» Main vein of thè thorax
D» Main vein of thè stomach.
Questions 31 — 35 (Use Fig» 2) i>
31» In thè organ in Fig» 2, A and B are outer layers, which 
is harder and why?
A. A because it is in cbntact during chewing.
B. A and B because they are in use in chewing 
CB B because it protects thè pulp cavity
D» All of thè above 
32. Why is layer B very hard?
A* To give protection to thè pulp cavity.
B» To protect thè cement
C. To protect thè enamel
D* To protect thè dentine
33» What do you think should be thè function of C?
A. To attach thè tooth to thè jaw
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B0 To attacb thè tooth to thè enamel.
C0 To attach thè tooth to living substances
D0 All of thè above,
34* What substances do you think D contains?
A* Nerves, capillaries and lyroph yessels.
B0 Nerves and blood
C* Nerves and Flesh
D* Blood and Flesh 
35* Which part of thè organ is E?
A* Jaw bone
B* Dentine
C, EnamLel 
D* Pulp cavity
36 £ 4Òt Use thè Information below to ànswer questions
36-40*
Class four biology students were engaged in a practical 
exercise* They were given three boiling tubes, A, B 
and C with a solution. Using thè solution in thè tubes, 
they were aske'd to followthe following procedure:
(i) In tube A, add blue Benedict’s solution and boil*
(ii) In tube B, add conc HC1 and boil for 10 minutes*
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324
(iii) To tube C, add iodine solution*
Now answer thè questions after thè conclusion of thè
procedureso
36» If thè solution in tube A gives an orange precipitate, 
which food substance do you think is present in thè 
solution?
A0 Glucose
B. Protein
C. F at
D. Sucrose
37. If thè solution in tube C turns blue-black, and if a 
fresh solution is put into another boiling tube D and 
then hydrolysed. What is thè food substance that 
would be thè result of thè hydrolysis?
A. Glucose
B. Sucrose
C. Starch
D. Protein
38. The tube C originally contains which food substance?
A. Starch
B* Glucose
t - ^
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C„ Sucrose 
D0 Protein
39o If thè solution in tube B gives urine-coloured solution, 
thè solution in B is likely to contain
A. Sucrose
B, Fat
C, Protein
D. Glucose
40* Xf thè solution in A consists of small units thè process 
by which thè units can result in a complax molecule is
called .....
A0 Condensation
B. Hydrolysis
C. Hydration 
D# Catalysis
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APPENDIX 7
Students psychomotor Test/Students
Psychomotor Assessment Inventory 
(SPT/SPAI)
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Stader.ts Psvchomotor Test
Requirements for thè exercises; 
lo Onion bulb 
20 lodine solution
3* Fehling*s Solutions I and II (mixed) 
4« Test—tubes
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Students Ps '̂chomotor Assessment 
Inventorv (SPAI)
Scorinq Key:
2 = Satisfactory manipulative behaviour
1 = Partially satisfactory manipulative behaviour
0 = Unsatisfactory manipulative behaviour
Criteria Exhibited 2 i 0
i. Sectìoning skill (correct piane of
section)
2. Addition of adequate number of lodine
dropfe
3* Addition of adequate nUmber of 
t’ehlihg^B solution I and li drops
4. Hethod of mixture and shaking of
mixture.
5. Heating techniques
6. Ease of handling apparatus
7. Accuracy of observation
8. Drawing skill (accuracy)
9, Qarrying out exercise to time
10. Accuracy of recording and reporting
observation.
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Students Psvchomotor (Manipulative Skill)
Test
( SPT)
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330
Students Psychomotor (Manipulatifre Sklll) Test)
This is a test oh how well you can use your banda*,, 
equipments and carry-out instructions»
This test is not an examination»
Name:
School:
Sex:
INSTRUCTIONS
On your tabie is specimen A. Examine thè specimen 
very well and carry-out thè following directives.
1, Cut; through thè specimen vertically to show all thè 
features, Draw and label what you see.
(15 minutes)
2« Add two drops of iodine solution onto thè cut $urfacea 
Record and explain what you find,
(10 minutes)
3» Add six drops of Fehling's solution I and II (this had 
been mixed for you) to a freshly cut surface (another 
surface)• What do you observe0 Record and explain 
what you observe.
(10 minutes)
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331
4o Put six drops of Fehling's solution I and II into a 
test-tube* Heat gently and observe* Record your
observation*
(10 minutes) 
Total time: 45 minutes
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a p p e n d i x  8
NOTES OF LESSON
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Treatment Conditions
The treatment was for 6 weeks*
The communicational strategies, was as previously 
determined with a pre-test and post-test of;
1» Students Attitudinal Test (SATT)
20 Students Psychomotor Test (SPT)
3« Students Achievement Test (SAT)
The communicational strategies amphasiìddd were ;
1» Questioning Styles;
Leading, probing and contextual questions 
2o Defined terms at first occurrence 
3# Locai specimen for illuistrations
4o Labelled diagtams and fcictures
5. Inquiry method
6« Challenging practical exercises»
As indicated, eight communicational strategies will be 
used* Since there are bound to be overlapping during 
teaching, attempt were made to delinate particular time 
interval when a communicational strategy was used»
Since treatment is for 6 weeks, each of thè eight 
communicational strategies was focussed at for specific
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334
time during thè treatment period.
TOPICS TRBATED 
WEEK 1: NUTRI^ION
l o Food for metabolismi
2. Holophytic, holozoic and saprophytic nutrition 
3. Minerai salts for mammals and angiòsperm 
4. Carbohydrates, fats and protein - composition, 
uses and theoretical description of food tests 
5. Vitamins - sources, functions and deficiency 
diseases.
WEEK 2:
i* Feeding methods Of animals -* herbivores, 
carnivores, omnivores, filter-feeders, 
parasites and sapJtophytes*
tiU DigestioH and ita Cohaequendes ** ihgestioh to 
assimilation and egestion: physical and 
Chemical digestion,
3o Mammalian teeth and jaws - tooth structure and 
types of teeth,
4» Herbivores and carnivores teeth and jaws»
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WEEK 3s
le Mammalian alimentary canal 
2r, Absorbtion of food at villi 
3® PRACTICALS
(a) Food test.
(b) Experiment with digestive enzymes.
WEEK 4Ì
là HerbiVores and carnivafeb; thè giit
2. Storage of food
3« The liver — functions
40 Diet: balanced diet, Kwanschiorkor.
«
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LESSON NOTES APPENDIX I: SHEET I
WEEK I: LESSON I (80 MINUTES)
m I
LESSON TIME WHAT TO TEACH MATERIALS HOW TO TEACH? - COMM. STUDENTS ACTIVITIESSTRATEGY —  - ------ —  - . L
FOODS & F FOOD p
FEEDING lo Food - Material for Comm. African building up of proto- Leading questioni 3  Examines thè materials 
plasm is of two types Food types: Mcihnasr:a ctWehraits tairces  tohfè  a provided on thè side 1. Beans  living matter? ta ble (Yam, beans 
(a) Inorganici Are simple 2. Rice ammonium salts) and  
mo}.ecles common to non- 3. Yam Locai specimen: identify thè  
5 Mins* l 4. Cassavacairvibnogn  mdaitotxeird e,em.gi.n èral 5. Water 2 mins: Yams,Beans,
differences between 
 
 Cassava an organic and 
salts and water. 6. Ammonium inorganic material.salts.
ì (b) Organici Are complex, 
carbon-containing com­
pound s e.g. carbohy— 
drates, fats, proteins •
and vitamins.
These classes of food, are 
characteristic of living 
matter.
METHODS OF NUTRITION
There are two differenfct 1. Green Probing questions: 3 Observe on thè micro­
methods of nutrition. plants mins.: If moist, scope slide; on thè 
la Autotrophic: Are organze 2. Fungi grown bread is left, for 5 morphological 
isms-plants containinq on breado days, what would be features of algae 
gnreeeedn  ocnlhyl or
observed? and fungi.
5 mins. in
ooprhgyalnli.c .Tfcey 
fo©d from which they 
synthesise organic 
motlreacpupleeda ,f roums insgu nleingehrtgy  
to drive thè reactions. ----------------- i-------
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LESSON TIME WHAT TO TEACH MATERIALS HOW TO TEACH» - COMM. STUDENTS ACTIVITIES
STRATEGY
5 Minso 20 Heterotrophic: Are orga- nisms-animals and non- 
green plants e.g. fungi» 
They feed on organic ir 
food» From this they 
derive their energy 
released by respiration,, 
They also need some 
inorganic food»
AUTOTROPHIC NUTRITION: lo Green 
F oloph'ytÌG angios- Terms defined: 2 Move out of thè class- 
j Examples: Typical green 1 ~ . a perms mins: Holophytic room to thè school 
plants e«g» spirogyra and garden and have dose 
T?ynpjeio soperms»
Contextual question: 
6 mins: look at thè green f jfood: Inorganic only plants»
e»g» carbon dioxide,water How do plants make 
and minèral salts» their food and what 
How thè food is used: are thè uses of food substances for 
8 mins: (i) Caarreb ocnodmiboixniedd e ina ndp hwoattoesr 
plants?
y- 
nthesis to make carbohy- 
drates»
(ii) Carbohydrates are modi- 
fied and often combined 
with salts to form other 
organic molecules e»g. 
protein
Source of energy: Sunlight 
trapped by chlorophyll . 
during photosynthesis»
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WEEK I SHEET 2
LESSON
TOPIC TIME WHAT TO TEACH? MATERIALS HOW TO TEACH? - COMM. STUDENTS ACTIVITIESSTRATEGA
HETEROTROPHIC NUTRITION
Source of energy: Rely on 
respiration of organic 1* slides of Leading questioni 2 States likely sources 
mwohliecchl ecso n—ta itnhè bonds of 
amoeba mins: Whnl oro thè 
 energy» Mas sourcos ol unurgy
of energy for man»
 
no chlorophyll hence no for hetorotrophs?
photosynthesiso
HOLOZOICs
Examples: Typical animals 
1 8 mins: e0g. amoeba and mammals»
Contextunl <|uuot ion: Examines thè movement 
Type of food: organic,water 6 mins: and feeding of amoeba 
Haonwd  mfionoedr aiis s
When a man takus under thè microscope»
 usaeldt:s *Food orga- food, thu qunntity  
nisms are killed; secreted of thè food whun  
i compared to thrs waste abnstoerrbneadl;l yji nsooilguebsltee d Pwraodsutcets egested indiente a  
egested (eliminated) » decrease. How do one account for thè 
differencu?
Saprophytic:
Examples: Bacteria and fungi 1. Slides of Defined tormx 2 mins: Muct>r growing on bread 
of decay e»g» mucor and fungi, Saprophytic» is brought to thè 
mushrooms* mucor and class and examined. 
4 mins* Type of food: Dead organic mushroom. Locai specimen: 2 Thereafter a discussion matters, water, and minerai mins* mone thtohde iri s fdeoendei»ng 
Hsoalwt sfoood is used: Dead c--- r-v- 1» Mucor on bread
organisms are digested by 2» Mushroom on dead 
enzymes secreted exter- wpod
nally onto them and 
soluble products absorbed»
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WEEK I SHEET ì 4
LESSON TIME WHAT TO TEACH? MATERIALS HOW TO TEACH7 -COMM. STUDENTS ACTIVITIES
TOPIC STRATEGY
FOODS & 
FEEDING FOOD CHAIN:Organic food can be obtained 1. Slides of  Defined termi 2 mins: Are to trace thè 
from living organisms Cholo- fungi, mucor  
zoic) or from dead matter and mush- 
Food Chain relationship between 
 man, fish, water and 
(saprophytic) resulting in room Inquiry method: water plants.
£ a chain of Holophytes live,
3 mins:
 
5 Mins. organic Holozoites food
If you have a situa- 
tion where you have 
man, fish and vege- 
Dead, organic food. table, how can you 
Inorganìc illustrate thè 1 food Saprophytes relationship be- tween thè three 
during feeding.
4 Min. Inorganic food include; Leading questioni 
water and minerai salts. 1 Min.: What are Identifies inorganic inorganic materials? food materials.
Minerai salts for M^mmals Source of 
and Angiosperms minerai salts.
Defined terms 1 Mina State thè constituents 
1. Milk Minferai.salts.Elementi Calcium (Ca) 2. Bread Locai specimen: 1
of bread and milk.
 
Source: Milk 3. Liver min: Milk, Bread. Uses: Bones, teeth, A.T.P. 4. EggSo Inquiry method: 2 and nicl eie. acid constiti*-» i- mins: If a child 
èntàci..»; . w  '  ̂ v §« Table salt is seen with brittle 
Qeftbiei.cy: Brittle bones 6. Water bones and teeth what 
and teeth. 7. Vegetables food substance does he need - offer 
suggestions
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WIl EUUEIK\ JI- s• SHEET 5
LESSON TIME WHAT TO TEACHT MATERIALS HOW TO TEACH? -COMM. TOPIC STRATEGY STUDENTS ACTIVITIES
FO Element: Phospt©rus (P) FEOEDDSI NG& Source: Milk, cheese and Contextual question:  
bread. 4 Mins: What are thè 
Identifies thè consti- 
uses of phosphorus tuents of A.T.P. and 4 mins: Uses: Bones and teeth are   
mainly calcium phosphate. in thè human body?
mucleic acid.
 
Deficiency: Brittle bones 
and teeth.
Element: Iron (Fe) Locai specimen: 2 
Source: Liver and egg yolk Mins: liver and egg. State thè function of 
i 4 mins: Uses; pare of haemoglobin haemoglobin in thè  Deficiency: Anaemia Probing question: human blood.
y2 oMui ntsh:i nkW hacta ndo  
cause anaemia?
Element: lodine (I)
Source: Sea foods and Locai specimen: 1  Min: Table set. State thè source and table salto Inquiry method: 3 use of table salt.4 Mins: Uses: Part ofhthyróxi&h Deficiency: Goitre-thyroid mins: suggest a  
swelling in adults. food substance for an adult with goitre
Element: Fluorine (F) 
Source: Fluorinated tooth Toothpaste Lmoinc:a i Tosoptehcpiampaste and water. s
etn.: 1 Identifies why tooth­ paste manufacturers 
4 Mins: Uses: Ensure hard tooth - Contextual question: thè enamel and therefore 3 mins: Why do you /n
add fluoride to their 
 
 
less tooth decay. think drinking water
pfcoduct.
 
 
Deficiency: Dentai causes is fluorinated and  
more likely. toothpaste manufac- turere add fluorides?
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WEEK I: SHEET 6
LESSON TIME WHAT TO TEACH? MATERIALS HOW TO TEACH?-COMM. STUDENTS ACTIVITIESTOPIC STRATEGY
Eiement: Sodita- (Na) Probing question: 3 Mins: What do you State thè uses and Soucce: Table salt (N; cl)  
Use: In association with Table Salt think can aid thè
functions of thè 
 nerves and muscles.
3 Mins: potassium for proper opfr ompuesre if uesn ctainod nin-ng functioning of nerves and  rves >
muscles. nerves?
Locai specimen: 1 
Min: Table Salts.
2 Mins: Eiement: Potassium (K)
Leading question: 2 Identify thè sources 
1 Source: Plant food Mins: What is thè of potassium*Use: As sodium richest source of potassium?
PLANTS NEEDS
Elements: Nitrogen (in 
Nitrates), Sulphur (in 1. Snoidtiruamt e Leading question:2 mins: What are thè Relate thè role of 2 mins: Sulphate) .  nitrates and sulpfcur Uses: Protein and nucleic 2. Sodium uses and thè likely 
acid synthesis. Sulphate deficiency of : i :r oc
to their origin and 
 Tfunctions.
Deficiency: Poor growth* nitrogen and sulphur.
ELEMENT: Phosphorus (P) 
Source: Phosphates PPohtoasspèhiautm Defined term: 2 2 Mins: Uses: A.T.P. in photosynthe** e Mins: Identify thè role of sis, respiration and phosphorus in plants*
nucleic acid synthesis. Photosynthesis. 
Deficiency: Poor growth.
Eiement: Potassium (K) in Defined term: 2 
Potassium salts. Mins: Identify thè source *>n 2 Mins:  Deficiency: Poor growth - Dehydration* and use of potassium.
dehydration.
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—
LESSON
TOPIC TIME WHAT TO TEACH? MATERIALS HOW TO TEACH?—COMM. STUDENTS ACTIVITIESSTRATEGY
Clemente: Iron (in Iron 
salt 1. Pale leaves Probing question: Identify thè source and 
4 Mins: Uses:
s ; Iraonnd:  Mafgonre eesnizuymm.e s 4 Mins: If you  
for making chlorophyllo 2. Ferrous find thè leaves
use of Iron salts in 
 
 plants.
Magnessium: Part §f chi : sulphate. of a plant pale,  
Chlorophyll molecule. what do you think  thè deficicncies 
Deficiency: Pale leaves will be?
(chloròsis)»
Trace Elements: C3o Mnitnesx.t:u al Waqtue satrieon:  Identify trace 
3 Mins.: They include: Zinc, copper and manganese are trace elements and  
required in minute in which quantities
elements.
 
 
quantities for healthy are they useful? 
growth.
Total SUMMARY
TOTAL TIME: 77 Mins. 
 periods). 1. Leading questions: (2 10 mins.
2. Probing questions:
12 mins.
3. Contextual ques­
tions: 2 mins.
4. Defined terms:
13 mins.
8. Locai specimen:
16 mins.
C. Inquiry method: <
8 mins. !
«
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WEEK X: LESSON 2 (80 MINS.) SHEET 8
WEEK I   LESSON TIME WHAT TO TEACH? MATERIALS HOW TO TEACH? - COMM. TOPIC t L .i.. . • STUDENTS ACTIVITIESLEBSON
2 . n. ... STRATEGY
per2i- ORGANIC c a r b o Ay  d r a t e s  
ods FOOD Eiements: C.H.>0. : 1. Giucose
of 1. Car- 
1 Min, Ratio of 2*1 as in H^O 2. Tabie sugar Leading questioni 1 Identify carbohydrate 
80 bohy- 3. Starch
min: Give a list containing Nigerian 
drate. 4. Benedici*s of thè eiements food.Mins. 2. Fat 5. solution
in carbohydrate?
3 « P ro— 1 Min.
Examples: Giucose ( C „ 0H 0 ) 5„ lodine
i-C. c. 5 6. Hydrochlo- Leading questioni 1 
ric acid min: Give examples
Examines thè types of 
 
tein Suorose <C12H22°16
carbohydrates in thè 
7. Six test- of carbohydrate. laboratory.
4. Vits tubes Units: Monosaccharides ( 8. Bursen 
-O (Simple sugars like olucoses. burner
Inquiry method: 2 Observe and state 
V» 2 mins. These are thè smallest unit
mins. If it is physical differences 
that are absoroed after diges-  possible to break- between giucose and 
stion hydrolysis)• They can down a big molecule to smaller units, starch.be reasembled into larger  
molecules again (condensation) how can one get 
when food needs to be stored smaller units from a molecule?
Larger Molecules: Disaccharides 
2 mins. e.g0 sucrose, maltose and
Locai specimen: 2 
 
polysaccharides e.g. starch, mins: Table sugar,
Taste sucrose and 
 
 starch. giucose and state glycogen and cellulose. differences.
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WEEK I: LESSON 2 SHEET 9
WEEK I LESSON TIME WHAT TO TEACH? MATERIALS HOW TO TEACH? -COMM. STUDENTS ACTIVITIES
LESSON TOPIC STRATEGY
..2 ■
CHEMICAL TESTS: Contextual questioni Observe teachers •k.mc-'-o 3 MinSo 1# Blue Benedict's solution 3 mins: If three demonstration and 
with reducing sugar when different Solutions state reasons for 
boiled gives orange are put in three deductions in thè 
precipitate. test-tubes to each experiment.
2„ Colourless concentrated of this if benedict’s 
hydrocholric acid and solution, conc HC1 
sucrose when boiled for and lodine solution i. 
ten minutes gives urine is added, what ; ; -1 coloured solution. changes would be observed?
3» Brown lodine solution and 
starch in cold gives 
blue—black
FUNCTIONS:
lo Energy supply when required; Inquire method: 3 State thè uses of 
3 Mins. stored as starch (green mins.: Determine thè chaumrabno hybdodrya.tes in thè plants) and glycogen uses of carbohydrate 
(animals); Transported as as a focd consti- 
sugars. tuent .
— 2« Structural: cellulose, cellwall.
3. Origin of other organic 
molecules e.g. sugar and 
naicitdr»ate that gives acetic 
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WEEK I: LESSON 2: SHEET 10
WEEK 1 LESSON TIME WHAT TO EACH? < «MATERIALS HOW TO TEACH?—COMM « 5TUDENTS activitiesI.KSSON TOPIC STRATEGY
2
1 Mine FATS (Solici) OILS (Liquid) 1. Mutton Elements: CfH,0« Ratio of H is v .*y fat
Leading questioni 1 Identify thè elements 
« min: What are thè Dresent in fatovery high to 0 . 2. Paper3. Suden III efalfe mc e.nts present in
. 40 Four test- 
1 Mino Examples: Mutton fat; C57H-̂ q̂ tubes « Locai specimen: 1 )bserve mutton fat on 
min: Mutton fats. thè demonstration table.
1 Min. Units: Glycerol and fatty tdentify thè differences 
acidSo Ln mutton fat and glycei? 
I rol0
Chemical tests:
lo Translucenctì^hen warmed on Probing questioni 
paper, makes paper permanen- 3 mins: What would Dbserve teachers demon­ 
tly translucent Cgreese spot) , you observe if fat stration and offer 3 Mins.   2o Red Sudan III stains fats apnadp eroil is warm on
axplanation for
 and if, to tire  fai »Dbserved phenomenon,intensely, so fat layer 
floating on watery food red Sudan III is 
esctract locicr- dark redo added?
Functions: Inquiry method: 3 
lo Energy supply: when respired, mins: When lots of . State thè sources and 
Used after carbohydrate, energy is required, a . 
Important in flying, migra- flying bird dlsco- 
runctions of fatty food 
substances in thè body.
5 Mins. tion and liberating animals» vers that all thè (Has more energy (i.e, Fats) carbohydrate energy' 
per unit mass than glycogeno hcis beon used, what 
2o Heat insulation: As sub- óther sources can he 
cutaneous fat in memmals, get itfts ènergy fròm? 3« Waterproofing of skin, far Probing question 2: 
and featherSo Mins:State thè ofher* ' 
4® Bonyancy e0g0 fish ?lgjrva'e functions that yòu 
in thè sea think fats and oìl^ r . cÀn be used. f o r j  "
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WEEK Is SHEET 11
WEEK I LESSON TIME WHAT TO TEACH? MATERIALS SHTORW ATTEOG YTRACliy-t mMM. *>; i11 m ir m ih ai rivi ti EU1issg a TOPIC
2
PROTEIN
1 Min* Element
Ss C,Ho0 ,N and often S. 1* Mutton fat 
20 Leading qu< a II. >nl 1 Egg Min! Wh.il tii III*' ili gii 1 1 11 al 1 lui e 1 pimmts 3* Millon's elemento pi < wmil  n H MltHll 1 II | S ul iiin.reagent proteina? 1  
4* NaCl 
1 Min* Examples: Haemoglobin, 5* CulSo 4 ptyalin and insulin. 6• Six test— tubeso Leading qu< ni Inni I Min: Givi «v.iinp  * Ilnln i >xniiip 1 i ih of 1 m 
of proti Inolio rumi noi ofu il ih  r t iod. 
substane t m.
|
1 Min* Unitsi / m'.no acida* Leading qui ni 1 ■ >n I min: Whnl in 1he Uni i' d.lfforonccs  
smallest. uni I or betwoon mono di, and h   l’o i y-molocules.
protein.
2 Mins* Earger molecules: Dipeptides 
(two linked amino acids) Defined tarmili 2 iduntify differences in  
polypeptide (MANY), Peptones minss Dopopl lduti, dopeptides, piblypeptides, 9  
(very many), Proteoses (nuch). Polypeptido», peptones and proteoses»peptones nnc1 
proteoses.
■ 3 Mins: Chemical Tests: Inquiry method* 5 lo Colourless Millions Solu­ Mins: How would one
State thè functions and 
 
tion plus protein, boi 1ed relate thè structure, sources of proteinous  
willgive brick red colcured units and Chemical food substances for thè   human body.
2* Cporlooteuirnl»
propertics of prot­
ess 40% Na OH and ein to it*s functions 
Protein extract with 2 in thè human body?
drops of blue Cuso^added 
will give mauve Bftiaret 
colour (Biuret test).
UNIVERSITY OF IBADAN LIBRARY 
347
WEEK I: SHEET 12
WEEK I I LLESSON t TIME WHAT TO TEACH? MATERIALS HOW TO TEACH? -COMM. STUDENTS ACTIVITIES
LESSON 'i ,toeic STRATEGY
2
5 Mins. FUNCTIONS:lo Energy supply wnerr* Inquiry method: 5 mins: How would one Sstoautrece st hèof  fpurnoctteiionno uasnd respired, Important  
in carnivores. relate thè structure
 
 food substances for thè 
2» Movement: Muscles contract units and Chemical 
fcendons connect muscles properties of protein
human body.
 
to bones; ligaments con­ to it’s functions in 
nect bone at joints all thè human body?
are protein.
3» Catalyst: Enzymes make 
metabolism reactions 
| 40 Hpoorsmsoinbelse.0 Regulate 
metabolism.
VITAMINS
5 Mins: They are organic substances Defined term: 5 mins: State thè characteris- . required in minute amounts tic and types of 
to maintain hsalth of hetero- lo Vitamins vitamins for thè human 
trophSo Antotrophs make all 20 Water soluble body.
they needo Lack of vitamin vitamins 
results in deficiency disease. 30 Hat soluble 
Vitamins A,D„E and K are fat vitamins. 
soluble and are ingested in 
fats and oil.
-  - — Vitamins B and C are water 
soluble and are present in 
other materials.
UNIVERSITY OF IBADAN LIBRARY 
WEEK I SHEET 13
WEEK I LESSON TIME WHAT TO TEACH? ÎATERIAL WHAT TO TEACH?-COMM « STUDENTS ACTIVITIESLESSON TOPIC STRATEGY
2
V \
2 Minso Vitamin A:
Source: Vegetables, butter, Locai specimen: 2 Identify thè sources of  
egg yolk and liver oil» min&s Vegetable, vitamin A»butter, egg and liver
2 Minso Functions: Ci) Health epithe— lia0 (ii) Part of rod cells Leading question: 2 
in retinac Mins: Sitate thè, func­ v
Sittaatmei nf uAn cttio onmsan »of 
tions of vitamin A„
2 Minso Deficiency: Ci) Susceptibi- Leading question: 2 Relate what can be 
1 lity to invasion by disease organisms, Ciì) Poor night mins: What are thè 
observed in a. man 
 consequencies of deficient of Vitamin 
Vision vitamin A deficiency» A.
2 Minso Vitamin D CSunshin vitamin) Locai specimen: 2 Identify thè sources Sources Butter, egg yolk» Ccan mins: Butter and of vitamin D*
be synthesised in thè skin egg yolk0
from cils irradicted by 
ultra~violet Cright)D
2 Minso Functions: Regulation of cal- Probing question: 2 mins: Can you state State function of cium and phosphate absorption  
-- .— -- ' from gut and their deposition thè function of
vitamin D„
 
in bone„ vitaftlin D in thè body»
2 Mins. Deficiency: Richetsi poor bone 
formation, was and often Contextual question: l State thè deficiency of 
deformedo e»g. bow legs in mins: Relate thè vitamin D in children. 
children» likely 8eficiency of vitamin D,
UNIVERSITY OF IBADAN LIBRARY 
349
 WEEK I: SHEET 14WEEK I  LESSON TIME WHAT TO TEACH? MATERIAL WHAT TO TEACH? -COMM. STUDENTS ACTIVITIESl.ESSON TOPIC STRATEGY
2
1 Min, Vitamin E
Source: Butter, whole meal 1, Butter
bread 2, Bread Locai specimen: 1 3, Yeast min: butter bread. Identify source of 
4, Liver vitamin E.
5, Milk
1 Min, Functions: Only in rate of 6, Vegetables
reproduction 7, Citrus fruits Leading question: 1 min: What are thè Svtiattaem inf unE.ctions of  
functions of vitamin 
E,
I 1 Min, Deficiency: Sterility in 
rat Defined term: 1 Min, State vitamin E &, Sterility. Deficiency.
* Deficiency Sterility in Defined term: 1 Min, 
ra< Go State vitamin E fertility Deficiency.
2 Mins, Vitamin K Contextual question: 
Source: Cabbage, spinach, 2 Mins: State thè Identify thè sources of  
made abundantly by sources where vita- vitamin K. 
bacteria in intestine min E can be got.
1 Min, Functions: Aids blood Defined term: 1 Min. State functions of 
■ -— _ — clothing Blood clotting. vitamin K,
1 Min, Deficiency: Longer Probing question: 1 bleeding time. min: If vitamin K is
State deficiency of 
 
absent in a man* s vitamin K. 
body, what are thè 
consequencies?
UNIVERSITY OF IBADAN LIBRARY 
35f
WEEK I : SHEET 15
WEEK I 
LESSO LESSOH tiT» wh • io , 1 .NLI- i m i Q TIME WHAT TO TEACH?
mot HSOTWR ATTEOG YTEACH?—COMM. STUDENTS ALT IV] Ttt.MMATERIAL
2 Mins. Vitamin B, (Thiamine) 
Source: Wholemeal bread, Locai specimen: 2  
yeast extract Mins: Bread and 
Identify source» of 
yeast extract. vitamin DI.
2 Mins. Function: Efficient 
respiration Defined term: 2 Min*: Respiration Svtiattaemi nf uBnlc.tions of 
2 Mins. Deficiency: -Beri—beri: Identify deficiencies 
Inflamed nerves and of vitamin Bl„
swollen heart muscles.
I
1 Mlns, Vitamin B2 complex (9 vitamins) Locai specimen: 2 
Source: Yeast extract and mins: Yeast extract
Rofe lattheè  atbhès ecnocnes eoqfuences  
liver» and liver»
 
vitamin B2„
2 Mins. Function: A variety of roles 
in metabolism Leading question: 2 Mins: State thè State thè functions of 
functions of vitamin vitamin B2.
B20
2 Mins. Deficiency: Skin, eye C2 onMitnesx:t uaRle laqtuees ttihoèn:  State thè consequences lesions (riboflavin); 
pellagra: gut problems, consequences of thè
of thè absence of 
 Vitamin B2.
paralysis, (nicotimic absence of vitamin 
acid) etCo B2.
1 Min: Vitamin B12 (Cobalamine) 
Source: Liver Locai specimen: 1 Min: Liver. Identify thè main source of vitamin B12.
UNIVERSITY OF IBADAN LIBRARY 
351
WEEK I: SHEET 16
WEEK I LESSON
LESSON 2 EOPIC TIME WHAT TO TEACH
MATERIALS HOW TO TEACH?—COMM„ STUDENTS ACTIVITIES
STRATEGY
2 Mins» Function: Aids formation 
of red blood cells, MPirnosb:i ngW hyq uedso tiyoonua 2  State thè functions think vitamin B12 is of vitamin B12»
important for thè 
body?
2 Minso Vitamin CSource: Citrus fruit, Locai specimen: 2  Minso Citrus fruits, vIidteanmtiinfy thè sources of milk and fresh 
vegetables milk and fresh
 CD
 
vegetables»
i 2 Mins» Function: Tissue-damage 
repair Contextual question: 0 2 Mins: State thè State thè functions of  
function of vitamin vitamin C,
c.
2 Mins„ Deficiency: Scruvy: 
Cgpiliary bleeding, poor Defined term: 2 Mins: Identify thè  
healing of wounds. Scurvy consequences of thè absence of VitaminCG-»
TOTAL TIME: 77 Minutes SUMMARY:lo Leading questions: 
2  P1r3 obmiinngs»0  questions: 
---- 13 Mins»
3» Contextual ques-tex "1
tions: 11 Minso
40 Defined terms:
15 Mins»
5» Locai specimen:
15 Mins»
6« Inquiry method: 
Mins»
UNIVERSITY OF IBADAN LIBRARY 
352
WEEK 2: LESSON 1L: (80 MINUTES) WEEK 2 SHEET I
WEEK 2 LESSON
LESSON 2 TOPIC TIME WHAT TO TEACH?
MATERIALS HOW TO TEACI It—COMM» STUDENTS ACTIVITIES
STRfiTEGY
Animals obtain food in 
one of thè following three Definod terms 5 Mins; 
ways: 1» Herbivores
Identify thè characler 
 
1. Às solids: Food organ­ li» Carnivores c
iasrtnìic voorf esh  erabnidvores,  
isms that have to be .il» Omnivores omnivores»
chgwed sitigli enough to vi» Solids and 
be digested» For liquids»
a* Beexrabmipvioeres eat plants 
b« carnivores eat animals 
c* Omnivores eat plants 
I and animaiSo
2» As solids in suspension 
Tiny food organisms in Leading questioni 3  lo Mussels 
water that must be 2o Slides of mins»: In case of 
Scatna ter ehcoowv ero rgsaònliisdms  
strained out of it» As kpthoytnoplan- 
water living phyto- 
in plankton—plants and planktons and filter-
food in suspension»
 
 
animals» For example 3» Microscope» feeders, how do they 
filter-feeders. obtain their food?
3o As liquids: 1» Slides of Defined term: 3 mins: Enumerate how parasites 
a* Juices extracted parasites Parasites saprophytes like mosquitoes and 
from living hosts, aód sapro— and nutrients» saprophytes get their 
without killing them» phytes.
b* e»g» parasites» Leading questioni 2 
nutrients»
mins: State how 
!>» Liquid nutrients Microscope animals obtain their 
produced by diges- food as liquid forms»
ting dead food 
externally and then 
sucking it up» e»g» 
saprophytes*
UNIVERSITY OF IBADAN LIBRARY 
WEEK 2 LESSON 2 SHEET 2
WEEK 2 LESSON  TOPIC TIME WHAT TO TEACH MATERIALS HOW TO TEACH? -COMM» LESSON 2 STRATEGY STUDENTS ACTIVITIES
\ Adaptation for Feeding
MethodS’J Leading questioni 2 Identify thè nature of - lo Herbivores: minsoi How are herbivores food*
Food does not run away herbivores adapted 
but large quantities for their feeding 
must be gathered since method»
their Food is relative- 
ly poor in qualityo
3 Mins. 2o Camivores:
Bave to capture and thè 1« Claws of Leading questioni 2 Identify thè nature ' f prey by cunninn as dogs, 2, Haunmiamnals» minsi Relate thè traps in spidtrs web,  teetho adaption of carnivo­
and source of carnivores 
poisons in cobra, and res for their feed­
f ood»
by use of sharp weapons ing method.
e»g. claws and teetho
2 MinSo 3 OOmnivores: Leading questionsi 2 
minsi How are omni- State thè nature and Adaptations for feeding  
are intermediate between 1 Cockroaches vores adopted for 
type of omnivores 
 
those of herbivores and their feeding method»
food»
 
carnivores e.g» human 
teetho They vary their 
food according to availa- 
bility e„g« cockroaches, 
rats, pigs and man»
UNIVERSITY OF IBADAN LIBRARY 
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WEEK 2: LESSDN 2: SHEET 3
LESSON TIME WHAT TO TEACH? MATERIALS HOW TO TEACH?—COMM. TOPIC STRATEGY STUDENTS ACTIVITIES
2 Mins. Mouthparts of herbivores, carnivores and omnivores. 1* Head of goat» Defined fcéng*a2 mins: These are basically in 2« Cockgroach Labrum.
Observed under thè 
microscope thè different 
4 parts:  teeth of herbi­i« Labrum: "Upper lip": Ar 3» Head of vores, carnivores and 
chemoreceptors - thè dog. omnivores.
tasting cells.
2 minso ii io Mianng disbulref ac{es awan"d)Grifi Defined term: 2 Mins: Mandible. Identify thè mandible  chopping surfaces» under thè microscope.
I
2 Minse iii» Maxilla ("lower lip") chemoreceptors. Defined term: 2 Mins. Identify thè maxilla 
--------- - •Maxilla under thè microscope.
2 Mins. iv. Labium {"Lower lip")» Defined tèfm: 2 Mins: Labium Identify thè labium under thè mkcroscope.
2 Mins» 40 Filter Feeders: Diagram of a Defined term: 2 Mins: 
Require sieves. Some v' *i whale Filter feeders. c
State thè nature and 
hcharacteristics of fil 
whales trap sTirimps on filter feeders.
frayed edges hanging 
down in their mouth 
cgvity, open to thè sea 
as they swim.
UNIVERSITY OF IBADAN LIBRARY 
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WEEK 2: LESSON 2: SHEET4
LESSON
TOPIC TTTBE WHAT TO TEACH? MATERIALS
HOW TO TEACH?-COMM» STUDENTS ACTIVITIES
STRATEGY
4 Mins. 5o Parasites:
(a) Ectobarasifces 1. Slide of Defind torm: 2 Mins; Enumerate thè nature r They bathe in nutri- tapeworm Endoparaoito.Probing quostion: 2 characteristics of tions liquids e.g« 
blood or digested 2. Microscope Mins: How do you 
acid filter feeders.
food in thè gut of think what endopara- 
bost, absorbing site survive in their 
food directly environmento
through thè skin or 
gut e.g. tapeworm.
2 Minse (b) Endoparasites:
1 Pierce their host to
1. Slide of 
mosquito Defined term: 1 Mins:  suck out nutritoliquids Endoparasites
Enumerate thè nature 
4 » and environment 
 
e.g. mosquitoes, flea 2* Microscope Locai specimen: 1: of ectoparasites.
and aphid.
! Mouthpart of ectoparasites 
(mcoquitoes) Locai specimen: 4 Observed and identify 
Apart from thè antennae there Mins: Mosquitoes - mouthparts. parts of a mosquito - are 4 basic parts in thè Làbium mandibJe,
raouth: lo Microscope Inquiry method: 6 Mins: Looking through maxi ila, hypophar
 ynx 
2 Mins. a. Labium: for sucking blood thè different sections and labium.up. 20 Slides of 
2 Mins. b0 Mandible: Sharp, for pie- thè various of thè ectoparasite rcing skin.
c. Hypotharynx: This is thè sections of 
mouthparts, how can 
' 2.Mins.  you relate thè struc—u 1 3duct that carries saliva thè mouth­ 
down to stop blood from parts «
tures to thè differ- 
 entf functions.
clotting.
2 Mins. d. Maxilla: Sharp, for pìer- cing skin0
2 . e. Labium: For support of mouthparts during pierc,’ 
! cing; protection; sensing 
purse of minute blood-
vessel to pumcture.
UNIVERSITY OF IBADAN
LIBRARY 
^ 5 5
WEEK 2: LESSON 2 SHEET 5
«
LESSON ITI ME WHAT TO TEACH? MATERIALS| HOW TO TEACH? -COMM» STRATEGY STUDENTE ACTIVITIESTOPIC
2 Mins* 6» Saproziotes:Need no jaws, only tubes Locai specimen: 2' Minsi Housefly* Iofd engtaipfryo ztohièt ensature for saliva down and *
liquid food up with pumps 
e»ge house£ly«
5 Mins» DIGESTION: Defined termi 2 Minsi All animals ingest food Digestione Enumerate thè basic pro­ 
through thè mouth into thè cess of digestione 
gut - except for parasites, Leading questioni 3 
In thè gut food is digested Minsi Briefly descr- 
physically and chemically* ibe thè process of food intake until 
i end of egestion.
5 Mins. a0 Physical digestioni Contextual questioni This is by chewing or 5 mins: Relate thè Describe thè processes  
grinding - as in herbi- process of physical in physical digestione 
voreSo This increases 
thè surface area of thè digestione 
food and makes it 
easier for Chemical 
digestione
3 MinSo b„ Chemical Digestioni Contextual questioni This is by enzymes which 3 minsi How will Describe thè   
hydrolyses large mole- you describe thè
processes involve in 
 
cules into smaller units, process of Chemical Chemical digestione 
so that it can be easily * digestion?absorbedo $4
f
UNIVERSITY OF IBADAN LIBRARY 
• m J
M»
M '
ktè
Dog akull (carnivora)
Hugo tem perai musei** 
to attow shaaring action 
of camaaaiaf kaath
Vary tight jolnt 
naadadif‘a 
ara to work
Masaater miraci*
topravant 
•Uugghnu pray Rodarti incraora Cha*
Stabbing teeth dMooating jawComa Miai teeth (or 
ahearing off meet, 
cracking bona
Thtck anatrai 
at front -  
aeffsharparang biada*
Shaap akull (harbivoro)
Homy pad (no I )
Smeli la m p o n i mi 
ter raiaing lower few
V«ry Io o m  Jolnt
•Itowinfl «deway» movwriM 
raadad fot ghndlng action
Oiaatama (noC)
Ridgad, file like, Huge maaaatar muaclaa 
continuouaiy growing grmUing laath (or rodUng jew aldeweya
PiG; 1 * Compamon of herbivore and carnivore jaw» and laetb
UNIVERSITY OF IBADAN LIBRARY 
M
Pari wom away
Enamel
(bardai than dentine: 
97%  eatckJin phosphate)
Dentine
(barder than bone)
’•*** Gum
Cameni 
(attaché* tooth 
toiaw)
Jaw  borie Pulp cavity 
(4 0 %  calcium Icontairik nerve 
phosphate) capillanea and (ymph veaaet»)
Closad root Opan root 
(poor blood supply: (for rapid continuoua rapiecament 
rapid replacement o( tooth «vorn away by 
noi needad) abrasiva food)
Canine tooth in jaw Molar ;ooth of herbtvoreRG ♦Vertical section ihrough two ktndi of tceth
/
V' I
%
UNIVERSITY OF IBADAN LIBRARY 
357
WEEK 2: LESSON 2: SHEF-.T 6
LESSON TIME WHAT TO TEACH? MATERIALS HOW TO TEACH? -COMM. STUDENTS ACTIVITIESTOPIC STRATEGY
3 MinSo Basic Hydrolysis reactions include: 1. Giocose Lmoicnsa:i  Gslpueccoismee,n:  st1 arch Enumerate thè nature Starch and water when Starch. and water. of an hydrolysis hydrolysed bv enzymes r xv Probing question: 2 reaction.
gives monosaccharides mins: What happens in a hydrolysis reaction?
2 Mins. 1. Fat and water can be hydrolysed by enzymes Locai specimen: 1 Min; 
to fatty acids and Mutton fat. Probing
Describe thè hydro­
 
glycerol. questioni 1 Minò
lysis of fat.
 
1 What is thè result if fat is hydrolysed.
2 Mins. 20 Protein and water can be hydrolysed by enz­ Pmrinosb:i ngW haquesymes to give amino t i
tsi otnh:è 2 Describe thè result of  
 result of protein thè hydrolysis of aci-ds«,  hydrolyses? protein.
PROCESSESs Inquiry method: 5 . i i.. • 
Absor£>ed food is then assi­ Describe thè basic 
milate^ - used or started in Mins: The process of processes of absorp-  hydrolysis, condensa­ tion and egestion.
thè body» Storage occurs tion and egestion 
when enzymes condense thè are necessairy during 
small units of foods into digestion and absor- 
large molecules. This is btion. How can one 
10 Mins. condensation, thè reverse of describe these proc- 
Ihnyddriogleyss
esses and when are 
tiesdo food is egested they necessary? 
(eliminateci) through thè Contextual question: 5 
anus0 Most animals have no 5 mins: What are thè 
enzymes to digest cellulose * roles of enzymes in 
herbivores have special hydrolysis and cond­
caedlalputlaotsieo.ns to digest 
ensation?
UNIVERSITY OF IBADAN LIBRARY 
358 ij.
WEEK 2; LESSON 2: ^ E E T  7
LTEOSPISCON TIME WHAT TO TEACH? MATERIALS HOW TO TEACH?—COMM o STRATEGY STUDENTS ACTIVITIES
TOTAL TIME: 79 Mins. SUMMARY
1 1» Leading questions: 14 Mins,
i 2, Probing questions: 9 Mins,
3, Contextual ques­
1 tions: 13 mins,
4, D2e3 fimn• - in
eudt etse,rms:
50 Locai specimen:
11 minutes,
6, Inquiry method:
11 minutes.
--------------------- - ---------- -— ■— — ------------------------------------------ -------------------------------------------
UNIVERSITY OF IBADAN LIBRARY 
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WEEK 2; LESSON 2: (80 MINUTES) SHEET 8
WEEK 2 LESSON TIME WHAT TO TEACH? MATERIALS HOW TO TEACH? -COMM, 
TOPIC STRATEGY STUDENTS ACTIVITIES
2 MAMMA-LIAN.-. 1 Min, Only vertebrates have their teeth differentiated - 1, Skeleton of  man with Defined term: 1 Min: Describe thè nature TEETH often into 4 types with   complete Vertebrates of thè human teeth.AND
JAW . . special uses« sLCeCtL lol fo
1 Min» Types of teeths 1, Incisers (I) For obta- Defined term: 1 min:  2, Upper and 
ining moufchfulls. lower jaw Incisors,
Identify thè incisors 
amongst human 
and teeth teeth.
1 ^ of human
1 Min, 2,Canine (C) For stalfc- skeleton, Defined term: 1 Min: bing and holding prey. Identify thè canine3, Upper and canine
(?■ , lower jaw n
and teeth 
1 Min» 3, Premolars (Pm) for :/~i 1— of goat, Defined term: 1 Min: 
grioding. Premolars, Identify thè premolar
4, Upper and
1 Min, 4, Molars (M) for lower jaw grinding. and teeth Defined term: 1 Min: of a dog. Molars Identify thè Molars,
2 Min, Dentai Formula:This is thè expression of Describe thè number 
each type of teeth, The top Defined term: 2 Mins: Incisors, canine line for thè number in premolars and molars 
upper half jaw while thè Dentai formulae thè human teeth.
lower line is for thè lower 
jaw.
2 Min, Milk teeth: Are thè first Defined term: 2 Mins:
set of teeth that are later Milk teeth. Enumerate what are : milkteeth.
shed.
UNIVERSITY OF IBADAN LIBRARY 
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WEEK 2: LESSON 2; SHEET__9
WEEEK : LESSON
LESSON HOW TO TEACH?—COMM•  2TOPIC TIME WHAT TO TEACH? MATERIALS STRATEGY STUDENTS ACTIVITIES
2
2 Mins. Back Molarsi Are adult 
set of teeth that are Defined termi 2 mins:  Back molars State what back later shed. molars
2 Minso Structure of teeth: Leading questioni 2 It consist of layers of mins: Briefly describe Oobf setrhvèe  thè model  modified bone nourised  cross section  thè structure of thè of human tooth.
from pulp cavity and shaped human tooth.
according to function.
1
i10 Minsa DIAGRAM OF STRUCTURE OF TEETH: Sectional Labelled diagram: 10 Observe and identify 
See Fig. 2: To be drawn on model of thè  mins: structure of various layers in 
a portabie board. human tooth thè tooth. tooth.
1 Min. Description of structure 
of tooth: 2 Portable 
Leading questioni 1 
board. min: How many parts Identify thè gum.Basically there are 8 can you identify in 
parts. a tooth?
1. The Gum
1 Min. 2. Enamel: Harder than Leading questioni 1 
dentine. min: What is thè >c Identify thè enamel. 
nature of thè enamel?
1 Min. 3. Dentine: Attaches Tu Leading questioni 1 
tooth to jaw. min: What is thè Identify thè dentine.
nature of Dentine.
UNIVERSITY OF IBADAN LIBRARY 
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WEEK 2: LESSON 2: SHEET 10
WEEK 2 
LESSON LESSON
Time WHAT TO TEACH? MATERIALS HOW TO TEACH?-COMM. STUDENTS ACTIVITIES
TOPIC STRATEGY
1 Min» 40 Coment-: Attaches tooth Leading question: 1 
to jaw. min: What is thè Identify thè cement 
position of thè 
cement in thè human 
tooth? ■
2 Minso 5* Pulp cavity: jcontains nerves, capillaries and 
lymph versels. Probing question: 2 mins: With thè posiV/ Describe thè nature  
/ tion of thè pulp ca.it
"and contents of thè 
 
cavity, what would be pulp cavity. 
it's constituents*
2 Minso 6. Open foot (only in herbivore molar tooth) Probing question 2 Identify thè *open 
for rapid continuous mins: What do you root*.
replacement of tooth think is thè function 
worn away by abrasive of thè open root in 
f ood. herbivoreso
2 Minso cloa lJcaiwu m bopnheo:s phlaatreg.ely of Contextual question: 2 mins: What is thè Identify thè nature of
nature of thè jaw thè jaw bone.
bone?
2 Minso 8* Close root in canina tooth) has poor blood Contextual question: Describe thè nature of
supply since rapid 2 mins: Describe thè thè close root.
replacement is not nature of thè close 
needed. root*
UNIVERSITY OF IBADAN LIBRARY 
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WEEK 2: LESSON 2: SHEET 11
T
WEEK 2 LESSON
LESSON TOPIC TIME WHAT TO TEACH1 MATERIALS HSOTRWA TTEOG YTEACH?—COMM'o STUDENTS ACTIVITIES
10 Mins Teeth and jaw: Carnivores 
(Dog siculi) See fig. 1A lo Upper  Labelled diagram: Obsérve and identify 
to be drawn on potable lower jaw  
board or cardboard. and teeth 
10 mins: Teeth and 
jaw carnivores. thè various layers of of a dog. a carnivores tooth.
1 Min, Description of herbivore 
teeth and jaw: 2. Portable Locai specimen
They also include various board» min: Upper Jaw
:  of1  Identify and state 
 
modificgtions. thè goat.
thè function of thè 
horny pad.
• 1 But one can recognise: lo A horny pad: To pulì 
grass (replaces Upper 
incisors)«
1 -Min. 2o Diastama (replaces thè Locai specimen: 1 
Canine min? Lower jaw of thè
Identify thè 
 diastema.
gort»
2 Mins» 3o Premolars and molars: Ridged, file-like. They Locai specimen: 2 Describe thè nature 
are continuously growing mins: Upper and and function of preno- 
grinding teeth. lower jaws of thè lars and molars.goat.
1 Min» F4.o rU urgo©ck imnags settheè r muscles: 
Inquiry method: 1 State thè function of 
jaws min: Relate thè thè masseter muscles.
sidewayso structure of mass­eter muscles to 
thè function.
UNIVERSITY OF IBADAN LIBRARY 
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WEEK 2: LESSON 2: SHEET 12
WEEK 2 LESSONTOPIC TIME WHAT TO TEACH? MATERIALS HOW TO TEACH?—COMM» STUDENTS ACTIVITIESLESSON STRATEGY
2 Mins. 50 Back joint: Unlike in 
carnivores, i£ is very Inquiry method: 2 State thè nature of 
loose to allow for mins: Relate thè  
sidev/ays movement needed position and struc-
and function of thè 
 back joint»
 
for grinding action ture of thè back j . v: 0 -------------- joint to their 
function.
2 Minso 6. Temporal muscles: Also unlike in carnivores, Inquiry method: 2 Identify thè nature of 
I they are small since 
mins: Relate thè 
they are needed ohly for structure of thè
thè temporal muscles»
 
raising thè lower jaw. temporal muscles to their function»
TOTAL TIME: 74 Minutes SUMMARY:
lo Labelled diagrams and pictures: 30 Mins, 
20 heading questions: 6 mins*
30 Rrobing questions: 7 mins»
4#, Contextual questions: 8 mins,
5» Pefined terms: 11 mins»
6® Locai specimen: 5 mins»
70 Inquiry method: 7 mins.
UNIVERSITY OF IBADAN LIBRARY 
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UNIVERSITY OF IBADAN LIBRARY 
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WEEK 3: LESSON I (80 MINUTES) SHEET I
LESSON
TOPIC TIME WHAT TO TEACH? MATERIALS HOW TO T EACH ? —COMM o STUDENTS ACTIVITIES
STRATEGY
1. MAMMALIAN 
ALIMENTARY 20 Minso See fig. 4: To be previous .y 1. Portable drawn on thè blackboard. black- Labelled diagram: 20 CANALo board. mi.nss Alimentary
Ddrifafwe raenndt  lpaaberlt  s tohfè  thè 
canal of man drawn human alimentary cgnal.
2. Treatment 2. C on thè board.
of food s
hhaorwtmg 
from
mouth to 15 Minso -Description of parts of 
thè hu­
anus. thè alimentary canal.
man ali­ Follow up thè teachers 
1. Buccal Cavity mentary description on thè 
2. i>alivary glands canal. chart of thè human l 3. Oesophagus Labelled picture 15 alimentary canal.
4. Stomach minsi Chart of thè 
-5. Gali bladder human alimentary 
6. Liver canal.
7. Pancreas
8. Small intestine
9. . CoRler10 ect»um.
The students are to iden- 
tify these areas on thè 
diagram.
1 Min. Treatment of food 1. Diagram during digestioni of thè human Leading questioni 1 Enumerate thè digestive   
1. Mouth: Food is Canal. min: What process process in thè  
ingested. goes on in thè mouth.2. Chart of mouth?
1 Min. 2. Buccal cavity: Food thè human Leading questioni 1 Enumerate thè process is masticated (chewed) alimentarycanal. min: What happens in thè buccal cavity.in thè buccal 
cavity?
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WEEK 3l LESSON 1: SHEET 2
LESSON TOPIC TIME WHAT TO TEACH? MATERIALS HOW TO TEACH?—COMM. STUDENTS ACTIVITIES
STRATEGY
1 Min. 3. Epiglottisi Prevent 
food entry into trachea. Leading question 1 
min: What is thè State thè functions  
role of thè of thè saliavary 
epiglottis? gland.
5 Mins. 4» Sglivary glands: Produce saliva - with Contextual question:  Describe thè nature 
neutral P.H. Here 5 mins: How would  you relate thè and functions of thè carbohydrate digestion   position and Chemic­ salivary glands.f b^'ins by action of 
ptyalin (salivary ) al constituents of  
umylase. Starch and thè salivary glands  to digestion?
glycogen is converted 
to maltose.
1 Min. 5o Oesophagus: Food Leading question: 1 
passage. min: What is thè Identify thè oeso­
role of thè phagus. 
oesophagus.
5 Mins. 6. Stomachi Contains 
thè gastric juice and Inquiry method: 5  Describe thè
hydrocholoric acid. C  • mins: Stomach is thè  1 digestive
contains clotting large part of thè  
enzyme. Contains Pep- alimentary canal. 
in thè stomach.
 
sin - enzyme v/hich Relate thè position  
changes protein to to thè function.peptones. There is  also 
Renin. There is also 
thè convertion of soluble' 
caseinogen (milk protein) 
to insoluble casein 
(curds)•
, _______ 1
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WEEK 3: LESSON 1: SHEET 3
LESSON TU ME . 7. - WHAT TO TEACH* MATERIALS HOW TO TEACH?—COMMo STUDENTS ACTIVITIES
TOPIC STRATEGY
1 Min. 7. Py.loric Sphlinter 
musele. Defined term: 1 Min. Identify thè pyloric « Pmyulseclrei.c splinter drop3.ets musele.
2 Mins. 8. Gali bladder: Stores 
bile. Bile is alkaline Leading questioni 2 
contains sodium bicarbo­ mins: What is thè 
State thè functions 
role of thè gali of thè gali bladder.nato. bladder.
1 Min. 9. Bile duct Dp-Fined term: 1 Min: Bile dpct. Identify thè bile duct.
2 Mins. 10. Duodenum: First part of smallintestine. Probing questioni 2 mins: Describe thè Identify thè duodemum.
position of thè 
deodenun.
10 Mins. 11. Liver. Produces biles The bile salts emusify Probing questionsi Describe thè functions 
fact globules into minute 2 mins: What is thè nature, secretion and secretion of sphlinter Bile pigments 
are by-products of red- i and function of thè 
thè liver.
blood cells breakdown» liver.
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WEEK 3: LESSON 1: SHEET 4
LESSON TIME WHAT TO TEACH? MATERIALS HOW TO TEACH?-COMM„ STUDENTS ACTIVITIESTOPIC STRATEGY
10 Minso 120 ^Pancreas- Contains thè pancreatic juice» It Defined terms: 2 mins: Pancreatic Iodf entthièfy thè position is alkaline containing   pancreas
sodium bicarbonate» Dig- jtiiee, starch» 
estion of carbohydrate trypsin and steap­
protein and fat conti- sin*
nu Locai specimen: 6 a* esCoarbohydrates are acted mins: Starch, 
on by thè panóféafeìc mutton fat, milk* 
aamnylase» 
Probing question:
d glycogCejnn vetrot sm alatmoyslea»se 2 mins: What is thè  
| b» For fat, steapsin
secretion and Che­
 
changes fat into fatty mical nature of thè  
acids and glycerol» pancreatic juice»\ l’or protein: Trypsin 
changes protein to 
peptones and peptides»
10 Mins. 13» Small Intestine» Defined term: 2 mins: 
It produces thè intestinal maltose, erepsin»
Identify thè position 
 
Juice and has a number of •: I n ' -. F Inquiry method: 
of thè small intestine 
6 in thè chart of thè 
glands» Food is absorbed mins: Quite a number human alimentary canal 
loto blood vesscl and of gland secretions 
laeteals within millions and intestinal juice
State thè end-product 
 
of villi in thè small are present in thè
of thè digestion of 
 carbohydrates and 
intestine* Digestion of small intestine» protein»
carbohydrate and protein Identify thè juices, 
continues. enzymes and their 
su Carbohydrate: Acted upon respective functions 
by many enzymes e»g» tnal- 
tase* Arts and changes mal- 
tose to glucose — all hydro- 
\ lysing dissacharides to 
monosaccharides.
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WEEK 3: LESSON 1: SHEET 5
LESSON TO\PIC TIME WHAT TO TEACH? MATERIALS HOW TO TEACH—COMMo STRATEGY STUDENTS ACTIVITIES
b® Protein: Acted on by 
many enzymes which are Contextual questions: 
together called erepsin. 2 mins: State thè 
Convertsall hydrolysing small intestine in 
peptones and peptides digestion and 
to' amino acids. absorption.
2 Minse 14» Appendix Defined term: 2 Mins: Appendix Identify thè appendix
2.Mins» 15. Caecum. CDaeefciunmed term: 2 Mins: Identify thè caecum.
2 Mins. 16o Large intestine: The 
vertical column is called Contextual question: Describe thè nature 
thè colono Has no enzymes. 2 mins: What diges­ and function of thè 
But water absorption tive process occurs 
takes place. in large intestine?
large intestine.
2 Mins» 17o PQCtum: tfaeces is Contextual question: 
formedo 2 mins: What is thè State thè processes  
function of thè at thè rectum. 
rectum?
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WEEK 3: LESSON & SHEET 6
LESSON TIME WHAT TO TEACH? MATERIALS HOW TO T EACH ? —C OMM o TOPIC STUDENTS ACTIVITIESSTRATEGY
180 Anus: Egastion of 
indigestible jfood and 
excess gut bacteriao Contextual question: 2 mins: State thè . .. • Dofe sctrhiè bea nutsh.è function role of thè Anus»
TOTAL TIME: 80 minutes SUMMARY
ì lo Leading questions: 6 mins0 
20 Probing questions: 6 mins*
3<, Contextual questions: 13 mins» 
40 Defined terms: 10 mins»
5o Locai specimen: 6 mins.
6o Inquiry method: 11 mins®
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WEEK 3: LESSON 2; SHEET 7 (80 MINUTES)______________________  T
LESSON TOPXC TIME WHAT TO TEACH? MATERIAL HOW TO TEACH7-COMM, STRATEGY STUDENTS ACTIVITIES
PRACTICAL
EXPERIENCE 5 Mins, FOOD TEST 1, Glucose CHALLENGING PRACTI- Carryout specified You are provided with two solution, CAL EXPERIENCES instruction, 
boiling tubes A and B 25 Mins; This is observe and 
with Solutions, 2, Starch individuai student record findings 
1, Take thè solution ir solution, practical exercises, 
tube A0 Pour a small 3, Four They are to provide 
and make deductions 
from findings.
quantity into a boiling students with unique 
clean test -tube. bubes per opportunities to student. study abstract 
1 4, Bursen concepto and gene- burner. ralisations through thè medium of reai 
materials.
5 Mins» 2, Then add few drops of Benedict solution.
5̂ Mi'nsr 3, Then boil thè consti- tuents for some èinutes»
5 Mins, 4, Observe thè solution and thè bottom of thè 
tub.
5 Mins, 5, Record your observa- 
tion and inferences on 
thè food substance in A,
NOTE; CONCLUSION;
A = Glucose,
B = Starcho
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WEEK 3: LESSON 2: SHEET 8
LESSON TOPIC TIME WHAT TO TEACH? MATERIAL HOW TO TEACH?-COMM. STUDENTS ACTIVITIES
STRATEGY
2 Minso INVESTIGATING THE EFFECTOF lo Starch CHALLENGING PRACTI- a0 Carry out instruc- t e m p e r a t u r e  on d i g e s =
TION OF STARCH BY SALIVARY solution* CEL EXERCISES 55 Mins:  
AMYLASE (PTYALIN) 2, 12 boil­ This exercise is to
tions.
 
ing tubes be performed by b. Observe and record 
You are provided with thè per group groups of four 
findings.
 
following: 3o Saliva students. It involves solution» thè students with e. State inferences from 
4, White tile opportunities to observed phenomenon.
ae six boiling tubes. 5« Bunsen study abstract con­
b  starch solution burner. cepii and generali- d. Give reasons for 0   e» saliva (diluted) - use observed phonomenon. 6» Ice bath sation using con­
your own, 7» Warm crete reai mater- 
Then carry on thè following water. ials.
instructionBo 8o wBaotileirng  
ioAdd 5 cm 3 0f thè starch 9. lodine 
solution to 5 boiling solution.
tubes« 10* Clock.
2 Mins» lo To another 4 boiling 
tubes add 1 cnr Qf saliva 
diluted with waterD
2 Mins® 2o P air up thè tubes in i) and B) so that you have 
five pairs (a tube with 
starch solution and 
another with saliva)*
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WEEK 3: LESSON 2: SHEET 9 fp
LESSON TOPIC TIME WHAT TO TEKCH? MATERIALS HOW TO TEACH?—COMM» STUDENT ACTIVITIESSTRATEGY
3 Minso 3-o Put a pair of each into these different conditions» 
ahoc  WIactee rb ataht room tempera­
ture» Q 
cu. Warm water (about 35»C) 
do Boiling water x 
e, This is thè controlJ To 
see if starch solution 
without enzymes will 
1 change» Here only one boiling tube (thè cne 
with only starch 
solution) should be put»
5 Minso 5» Leave thè starch solution and thè saliva for 3 
minutes in a water bath0
8 Mins» 6» Pour thè saliva into thè tube with starch solu­
tion next to it, mixing 
it as you pour» You are t< '
to do this for thè tubes 
in A — D of (4)»
7, Using.~a -dropper test
one drop from each boil- 
7 ìng tube with lodine* 
Fiiordsitn e pauntdc a thderno pcfbrfo m each 
of thè boiling tubes A—
D put in .a solution to 
each on thè iodine . . 
drop»
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WEEK 3: SHEET 16 LESSON 2
LESSON TOPIC TIME WHAT TO TEACH? M’* aterial s • HOW-TO TEACH?-COMM, <JS STUDENTS ACTIVITIES.* mi *. STRATEGY
5 Mins,, 8, N<pte fche time when each 
drop no longer turns thè 
iodine blue-black (that 
is when thè starch is 
diqested),
5 Mins, 0, Record your observation 
and inferences
f 6, Minso 10, N .iw put thè boiling tubes A-D into warm 
water and test after 
5 mins»
2 Mins, 11, NIow observe and note 
‘,he colour of A and D,
2 Minso 12* Looking at E and C how can you describe 
thè diqestion process.
2 Mins, 13, Using A, what can you 
............................. conclude
2 Minso 14, Using D what can you 
say^ ' v
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WEEK 3: LESSON 2: SHEET 11
LESSON TOPIC TIME WHAT TO TEACH? MATERIALS HOW TO TEACH7-COMM. 
STRATEGY STUDENTS ACTIVITIES
NOTE:
lo Colour of A is dark 
brown,
20 Colour of D is blue- 
black
30 Digestion at A,E and C 
are faster at w^rm 
i temperature.,
40 With A at low tempera­
ture, enzyme is inactive 
n but not destroyedo
TOTAL TIME: 80 minutes SUMMARY
Challenging 
Practical Exercises 
• 80 minutes»
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WEEK 4: LESSON 1 (80 MINSo) SHEET 1
LESSON TOPIC TIME WHAT TO TEACH? MATERIALS HOW TO TEACH-COMMo STUDENTS ACTIVITIESSTRATEGY
ABSORPTION 
OF FOOD AT 10 Minso See Fig„ 31 B: %ò be drawn 1« Diagram of thè villi Labelled diagram:on thè board» 10 mins: Enlarge Observe and identify VILLI on portable  longitudinal section various parts of thè board.  of a villi villi.
2 Minso Description of absorption 2o Slide of  Probing questions: 2 
Tat viili ©
thè section 
of small mins: How would you State thè functions of thè small intestine and 
ihs e resltartuecdt urteo  otfh è thfèu ncvtililoin  instestine. describe thè struc­ture of viIlio thè villio
! . of absorption that it performso 3. Microse- cope.
2 Mins. lo Epithelium: It is thè thin outer layer of Leading question: 2 mins: What is thè De
thè villi» nature of thè epithe- thè
s creipbiteh etlhièu mn.ature of 
lium»
5 Minso 20 Ctahpèi lwlaatreire ss:o lTuhbelye  cfaorordy Defined term: 5 Mins:  CapillarieSo State thè functions subfetanceso These are of thè ilafciillarieso
monosaccharides- amino 
aids, vitamins C, 
salta and water0
5 Mi’nSo 3„ Lacteal: It carries Defined term: 2 Mins: 
fatty substances, these Lacteal« Leading Enumerate thè role 
are f tty acids and question: 2 mins. of thè lacteal.
glycerol fat dropleis, What type of mater- 
vitamins A.D0E and K„ ials are carried in 
thè lacteal?
UNIVERSITY OF IBADAN LIBRARY 
"
.. S  y m
Water
* •* v% , ; *
•h W  * '• ' ;1 J>
m  "n~  / 
. '%*, -■ 
i
A italiota
>  io thoracic duci
.....»m ain vain of
■* ,•:•<- i Fot parìataWa: («fi arm
{ circular muleta longitudine! mulete
' .■  V■;( 1. < Ìt
(b| Parlatalata Imaans crf movtng food a long gut)
Succaasrva con trac bona 
of circular muactaa
Bolua o( food baing imovad along inaida
pic.;A (a) Enlarged longitudini! jection of a rillua (milbona lining tb a u n iil mlaauna) (b) P*n»iil*i»
■*.«rv ■
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376 I
WEEK 4: LESSON ls SHEET 2
LESSON TOPIC TIME WHAT TO TEACH? MATERIALS ' ‘... fTOW TO TEACH-COMM. 
STRATEGY STUDENTS ACTIVITIES
2 Mins. 4« Arteriole: From where 
blood is supplied to Defined term: 2 Mins. Identify thè  
thè villi» Arteriole arteriole.
2 Mins$ 5. Intestinal juice is 
also supplied to thè Probing questions: mins: With thè DJeusiccer.ibe thè intestinal 0 villi from thè surro- 2   
unding glands. wnhaetruer e doo f yotuh è tvhiinlkli  
ctOhmèe si ntferosmt?inal juice 
5 Minse 6 0 Venule: It carries blood from thè villi Leading question: 5  
to thè liver through amins: What is thè 
Identify thè venule.
 
thè hepati portai nature and charact-  
vein« eristics of thè v venule? .?
S Mins. 7, The -lact£al-;;al30 goes to thefmain veio.-.Of thè Probing question; 5 Identify thè lacteal.
left ariti; through thè mins: What is thè 
thoracic duct. direction of flow of thè lacteal?
8 Mins.
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WEEK 4: LESSON 1 : SHEET 3
LESSON TOPIC TIME WHAT TO TEACH? MATERIALS HOW TO TEACH?—COMM» STRATEGY STUDENTS ACTIVITIES
8 MinSo 8f For peristalsis move­ment, thè villi has ' ■ Probing question:  
three layers of muscles 3 Mins: What is  
surrounding thè exterioro Vtihlèl in Ihese are:  
ataundr e hoofw  itshè  
io Binding tissue: Outer this related to  
most layer» peristalsis move­ment?
iio Longitudinal muscles Contextual question: 
iiio Inner most circular 5 mins: What are
Enneucmeesrsaat rey  ftohrè factors  
l muscle» thè types and layers peristalsis movement»of muscle in thè 
villi?
5 Mins» Peristalsis movement: Labelled diagram:
See fig» 2b» Can be 5 mins: Peristalsis
Observe and discuss 
 peristalsis movement 
 
drawn on thè board» movement. as in thè diagram»
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WEEK 4: SHEET 4
—
LESSON TOPIC TIME WHAT TO TEACH? MATERIALS HOW TO TEACH?-COMM. 
STRATEGY STUDENTS ACTIVITIES
12 Mins. Description of peristalsis 
(With thè aid of Fig 3b): Inquiry Method: 12 mins: When a defla- Using fig. 3b, 
This is one means of ted bicycle tube is observe and 
movingfood along thè gut. about to be inflated, describe thè 
Since thè small intestine as air is gradually introduced, thè move- nature of has by means of their peristalsis 
circular and longitudinal ment of thè air can 
muscles to move thè food gradually be seen 
movement.
through thè gut. As thè as if is being 
food moves forward there inflated. If you | is a zone of contraction ó imagine thè air in 
immediately after tbe thè tube to be food 
bolus of food resulting and thè bicycle tube 
from sucessive contrac- to be thè small 
tions of thè'circular intestine* thè 
muscles. By this series peristalsis movement 
of contractions, thè food can be appreciated. 
is moved forward. With thè structure of thè small intest­
ine* how do you think 
food would be moved 
up to thè large 
j intestina.
2 Mins» Herbivores and Carnivores 
gut: 1. Slide on Locai specimen: 2 Describe thè gut of 
Carnivores: Short gut - thè section 
i this is because their of thè herb- 
mins: Dissected dog 
; vores and to show thè gut - a
carnivore, (dog).
 
j food is largely protein  carnivores preserve a specimen
! which is easy to digest. gut.
Il 2. Micros­
! cope.
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WEEK 4: SHEET 5
LESSON TOPIC TIME WHAT TO TEACH? MATERIALS HOW TO TEACH-COMMo 
STRATEGY STUDENTS ACTIVITIES
8 MinSo Herbivoress The gut is long» Sirice no animals has Locai specimen: 2  Enumerate thè gut 
a cellulose digesting mins: Dissected dog  
enzymes, they are aided by to show thè gut - 
and nature of an 
 a préserved speci­ herbivore (rabbit)obacteria which have cellu- (J
lase„ The bacteria have men*. 
in synbiosis in rumen of 
rujninants e»g» as in cow Contextual question: 
and sheep or caecum as in 4 mins: What is thè  
horses and rabbits» nature of thè gut in 
Rabbits eat their green herbivores and how  
j nutritious faeces from
does this affect 
 
flret' passage through thè digestion and  
gut ("reflection"), reflection in rabbits  
absorbing more food during and sheep? 
second passagec Horses 
do not reflect»
TOTAL TIME: 80 MINUTES» SUMMARY:
2loo  PLreoabdiinngg  qquueessttiioonnss::  91 2 mimnisn»s»
3» Contextual questions: 9 mins» 
4» Defined terms: 13 mins.
50 Locai specimen: 10 mins»
6„ Inquiry method: 12 mins.
7„ Labelled diagrams: 15 mins»
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WEEK 4: LESSON 2: (80 MINUTES) SHEET 6
LESSON TOPIC TIME WHAT TO TEACH? MATERIALS HOW TO TEACH?—COMM. 
STRATEGY STUDENTS ACTIVITIES
5 Mins. Food Is usually stored in 
three different ways. lo Chart of thè human Locai specimen: 3  mins: Glucose, State thè naturai 
1„ Monosacharides: e.g. alimentary liver.
form of glucose and 
«tarchj thè stored form.
Glucogen in thè liver canal»
and muscles. The excess Leading questioni 2 
if converted to fats 2o Diagram mins: What food 
and stored under thè of thè human 
skin. alimentary
substances are 
 stored in thè 
canal. body?
5 Minso 2. Amino substances: They 
are stored in thè liver- Leading questioni 5 
in mins: Where are 
State thè form in 
which fatty substances 
A,  Da d—d itainod n untdo erv ittahmèins fatty substances stored in thè body? are stored.
, skìtis
10 Mins. 3  Am/m o nia0 1 acids: They are 
not stored. They are Probing questioni 
used immediately» The 10 mins: Amino acids
Enumerate how amino 
 acids are stored 
ji excess is de-aminated are known not to be and eliminated.in thè liver to give stored -in thè body. 
two parts; How does thè body gets rid of them and 
i. Nitrogen containing in what form?
i
bpeacrotm e-s  aumrrecar ù-a  wehxiecrhe ted 
! by thè kidney.< iio The remainder can be 
i respired - used as f uel o A
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WEEK 4: LES SON 2: SHEET 7
LESSON TOPIC TIME WHAT TO TEACH? MATERIALS HOW TO TEACH7-COMM. 
' \ STRATEGY
STUDENTS ACTIVITIES
10 Mins* Liver:
Structure: It is a large 
organ, concerned with Defined term: 3 
homoestatis by metabolis—. mins: Liver,,
Doscribu thè 
structure 
ing food and poisons and Contextual question: of thè live
arn.d nature 
removing unwanted cells0 
They store foods and 7 mins: How can you 
blood. Receives Slcod relate thè structure 
from two sources, thè of thè liver to it*s i hepatic artery through function of diges- 
thè aorta and thè hepatic Htoionportai vein0 It’s blood w 
 doaensd  Sitt orgaegte? - *  
supply passes back it's blood supply?
through thè hepatic vein 
atol sot hèd ivsecnhaaercgaevsa ,b iIlte 0 •
*
2 Mins, Functions of thè liver:
lo Stores glucose as
glycogen, hydrolysing Leading question: 2 
it back to glucose mins: How is glucose 
Enumerate thè 
when neededo stored in thè body 
functions of thè 
and how is it utilize< .liver.1
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WEEK 4; LESSON 2: SHEET 8
LESSON
TOPIC TIME WHAT TO TEACH? MATERIALS HOW TO TEACH?-COMM„ STRATEGY STUDENTS ACTIVITIES
2 MinSo 2 o Stores vitamins A and Probing questioni 
B12 2 minsi Where do you 
Eunctions of thè 
think vitamins A, D liver conto
and B^2 is kept in
thè body?
5 MinSo 3» Stores iron from wor'n out red blood cells, Contextual questioni Eunctions of thè 
| ve/hich
5 minsi How is iron liver cont.
xcre biintg  brbeialkes  pidogw-n,  recovered from red 
ments in thè processo blood cells and reexlcarteet iotnh iso f tbo iltehè  
pigments?
5 Mins<, 40 Dep-raomtiemàant epsr odeuxccees surea Inquiry methodi 5 Functions of thè 
from thè process into minsi Urea has a liver conto
thè bHood for excre- purgent smeli, how 
tion 3ay thè kidneys» is it formed and which food subitanee 
do you think is thè 
primary source?
2 MinSo 5» Makes lolood protein e0g0 fibrinogen for Defined termi 2 Functions of thè 
clotting» minsi Fibrinogeno liver conto
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WEEK 4: LEi>SON 2: SHEET 9
LESSON
TOPIC TIME WHAT TO TEACH? MATERIALS HSOTWRA TTEOG YTEACH?-COMM»  STUDENTS ACTIVITIES
2 Minso 6a Makes bile saltsffor eroulsifying fats in Leading questioni 
intestine» 2 mins: What consti- 
functions of thè 
tuent of thè secre- liver conto
tions of thè liver 
aids fat diges- 
tion?
i 2 Mins. 70 Makes poison harmless e.g, ethanol drink or Locai specimen: 2 Tnins: Ethanol Functions of thè poisons from gut liver conto
bacteria drink»
2 Mins* 80 Filters out pathogens e.g» bacteria protcgoa Probing ques
in thè blood, using 2 mins: How 
tairoens:  Functions of thè liver conto
clealrlgseo phagócytic 
pathogens got out 
of thè body»
...........
ji ?.. Min S o 90 Produces heat from metabolism which -Leading questioni Functions of thè 
f1 assist in temperature 2. mins: How are 
t regulation» temperature regula- 
liver conto
l tion achieved?
j
5 Minso DIET:A balanced diet is one t! '■ 
that maintains health» It. Locai specimen: 2 minss Beans, rice, State thè different differs according to age; maize, meat, castor (common types) of occupation, climate and 
sax» oli, -fish, meat,
Nigerian food 
 
veg 'substancesoDefeitnaebdl etseor m: 2 
1 mina: Balanced diet»
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384
WEEK 4: ^ESSON 2: SHEET 10
LESSON
TOPIC TIME WHAT TO TEACH? MATERIALS HSTORWA TTEOG YTEACH?—COMM* STUDENTS ACTIVITIES
3 Minso CONSTITUENTS OF A DIET: Incjuiry method:
3 rnins: People of Enumerate thè merits (a) Energy — according to 
requirements - Carbo- different ages, 
of a balanced diet*
hydrates and fats* sek and climate, do different jobs, 
how can one relate 
thcir occupation 
to thè needs?
3 Minso (b) Materials for growth and repairs - provided Locai specimen:f  by proteins. 3 rnins: Scurces of 
State thè role of 
protein - beans, proteins in thè body
me^t»
3 Minso (c) Co-factors for enzymes 
to work - provided Defrined term: State thè role of  
by vitaminso 3 rnins: co-factors co-factors in thè human body*
3 Mins<, (d) Salts - to replace Coritextual questions: 
those lost in ®weat„ 2 rnins: Sweat is Idenfify thè role of 
sal-ty, how and why salts in thè body*
docs thè body need 
saLts?
2„Mins» (e) Water Locai specimen: 2 mins: Water* Identìfy thè role of water in human diet*
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WEEK 4*5 LESSON 2: SHEET 11
LESSON
TOPIC TIME WHAT TO TESCHI materiale . .... HOW TO.. TEACH?—COMM. STRATEGY STUDENTS ACTIVI» TIES
2 Mins. (f) RoOghage - indicesti*» ble bulk to help D emfiinnse;d term: State thè peristalsis^ 2  Roughage® functions of roughage®
5 Mins» Note:
Ftihrès te icglhats sa mipnroot caincsi dsc ontthain Inquiry method:man can not makc^ on his at  5 mins: Kwashior­
Enumerate thè 
kor is a common nature, function own. Animai protcein rich  
1 ìnl’Bherri plant pb'otein deficiency amongst
and deficiency 
 
 of first class 
usually poor. Wì_thout them, low protein feeding  proteins.
kwashiorkor resoilts (was- Asferei caa nmso,t heIfr  wyiotuh  ting of limbs, Jbot-belly   
full of fluid ocicurs when a child suffering one feeds mainly- on maize  — from kwashiorkor,  
with only seconc^ class .r- . what type of food  
proteine Beans ^ re richer nutrtients do you  
1 in first class Pirotein® or would you suggest for thè 
* child.ft1! TOTAL TIME: 79 MINUTES, SUMMARY:
} lo Leading questions: 13 mins.
ì :END OF TREATMENT, 2 ® Contextual questions: 14 mins.
! 3, Locai specimen: 12 mins.! 4, Probing questions:
ì 5, Defined terms: 13
14 mins.
mins.
j 6, Inquiry method: 13 mins®«ir
!
__.. i _ .. _
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i
386
WEEK 4: LESSON 2: SHEET 12
LESSON STUDENTS
TOPIC TIME WHAT TO TEACH? MATERIALS HSOTWR 
ACTIVITIES
ATTEO GYTEACH?—COMMo .• 1 
OSCUAMTMIAORNY  TOFO  CTOIMMEM UANLIL—=.  
CATIONAL STRATEGY
io Challenging 
Practical Exerc- 
isess 80 mins,
2* I-abelled diagrams 
and pictures: 80 mins,
3a Inquiry method*
72 minSo
40 Locai specimen:
79 mins,
5c D95e fminiends terms:0
S 0 Contextual 
questions: 90 
mins,
70 Probing Questions:
73 minSo
8. Leading questions: 
71 mins,
TOTAL: 640 minutes
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