COMPARATIVE EFFECTIVENESS OF TWO PROBLEM- SOLVING TEACHING APPROACHES ON SENIOR SECONDARY SCHOOL STUDENTS’ ATTITUDE TO AND ACHIEVEMENT IN PRACTICAL CHEMISTRY BY Y Ore-ofe Modupe APARA RA R B.Sc Biochemistry (Ilorin), PGDE (Ibadan), M. Ed EducatiIoBnal Evaluation (Ibadan) N L Matric No: 119132 A AD A Thesis in International Cent rIeB for Educational Evaluation Submitted t oO the F Institute of Education In partial fulfillTmeYnt of the requirements for the Degree of SI ER DOCTOR OF PHILOSOPHY IV Of the UN UNIVERSITY OF IBADAN JULY, 2015 i DEDICATION This work is dedicated to: My Father, late Chief Joseph Ojo Falana, whose wish was that I would become a medical doctor. And to Y My grand son R Oluwajomiloju Odindiloluwa Afolabi. BR A I L N AD A F I B O TY RS I E V UN I ii ABSTRACT It has been observed that many secondary school students in Nigerian perform poorly in chemistry. This may be attributed to the teaching methods used by their teachers as well as inadequate provision of practical materials and activities. Very often, students only observe experiments, copy notes and draw diagrams during chemistry lessons. Studies have revealed that students do not actively and effectively take part in practical chemistry exercises and this may be part of the reasons for their poor performance in the subject. This study, therefore examined the extent to which Laboratory Problem-Solving Model (LAPSOM) and Hands-on, Minds-on Problem-Solving Model (HAMPSOM) improved students‟ attitude to and achievement in practical chemistry. It further determined the moderating effects of chemistry process skills and class size. Y A pretest-posttest, control group quasi experimental design with a 3 x 2 x 2 factorial mRatrix was used. From the eight educational zones in Oyo State, three were randomly selectedA from Ibadan and Oyo towns. Three Local Government Areas (LGAs) were chosen based on Rthe geographical location from each of the selected zones. Nine public senior secondary schools were randomly chosen from the selected LGAs. Nine intact classes of 359 students pIaBrticipated and were assigned to LAPSOM, HAMPSOM and control groups. Treatmen tL lasted six weeks. The instruments used were: Chemistry Achievement Test (r=0.79), SNtudents‟ Attitude to Practical Chemistry Scale (r=0.85), Chemistry Process Skills Rating Scale (r=0.78). LAPSOM, HAMPSOM, and Conventional Method. Seven null hypotheAses were tested at 0.05 level of significance. Data were analysed using ANCOVA. D There was a significant main effect of the treatmenAts on students‟ achievement in practical 2 2 chemistry (F(2,346)=13.03, η =0.070, R =.176). St uIdBents exposed to HAMPSOM performed better (x=20.02) than those in LAPSOM (x=18.64) and the control group (x=15.09). There was no significant main effect of the treatments on Fstudents‟ attitude to practical chemistry. Both high and low chemistry process skills had significant effect on students‟ achievement in practical 2 2 chemistry (F(1,346)=10.15, η =0.029, R =O.176). Students exposed to HAMPSOM with high skill performed best (x=47.16) followedY by those exposed to LAPSOM (x=40.79) and control (x= 40.29). Chemistry process skilTls had no significant effect on students‟ attitude to practical chemistry. Large and small class sizes had significant effect on students‟ achievement in 2 2 practical chemistry (F(1,346)S=14I.54, η =0.04, R =.176) but students in small class performed better (x=19.43) than those Rin large class (x=16.38). There was no effect on students‟ attitude to practical chemistry, even though students in large class had better attitude (x=92.17) than those in small class (x=9E0.65). There was a significant interaction effect of treatments and chemistry 2 2process skills on students‟ attitude to practical chemistry (F(2,346)=3.31, η =0.019, R =.032) and 2 2 also students‟I aVchievement in practical chemistry (F(2,346)=5.11, η =0.029, R =.176). The other two-way aNnd three-way interactions had no significant effects on both. HandsU-on and Minds-on problem-solving approach had greater impact than Laboratory problem-solving approach on students‟ attitude to and achievement in chemistry. Teachers should therefore employ Hands-on and Minds-on problem-solving approach in teaching chemistry. Key words: Hands-on and Minds-on problem-solving approach, Laboratory problem-solving approach, Students‟ attitude to and achievement in chemistry, Senior secondary school. Word count: 484. iii AKNOWLEDGEMENTS I give glory, honour and adoration to God Almighty my Alpha and Omega for the divine provision and assistance throughout this research. I am very grateful to my supervisor, Prof. T. W. Yoloye for the sacrifices in going through this work. I also express my profound gratitude to Dr. Modupe. M. Osokoya, Dr. B. A. Adegoke and Dr. J. O. Adeleke for their un-relentless effort, patience, encouragementY and suggestions, which immensely contributed to the successful completion of this reAseaRrch. God will perfect everything that are yours in Jesus name. R I am particularly grateful to the Director of the Institute of EducatiIonB, Prof. E. Adenike. Emeke and the immediate past Director of the Institute of Education, PLrof. M .A. C. Araromi. I acknowledge the contributions of other lecturers in the Institute oNf Ed ucation for their different roles: Emeritus Prof. P. A. I. Obanya, Dr. J. A. AdegbileA, Dr. Folajogun. V. Falaye, Dr. Georgina. N. Obaitan, Dr. Ifeoma. M. Isiugo-Abanihe, DDr. Eugenia. A. Okwilagwe, Dr. J. G. Adewale, Dr. A. O. Umoru-Onuka, Dr. F. O. Ibode, ADr. Monica. N. Odinko, Dr. Serifat. F. Akorede, Dr. E. O. Babatunde , Dr. J. O. Abijo anIdB Dr. A. O Otunla. Dr Ajala of Social Welfare Department, God will continue to increase yoFu in Jesus name. I sincerely appreciate the efforts o f Othe following chemistry teachers in the various schools used for the study, Mr Fagbenro,Y Mrs Akinyede, Mr Adewusi, Mrs Ola, Mr Popoola, Mrs Gbadebo, Mr Ajadi, Mr JolasuInT, Mrs Olatunji, Mr Gbadamosi. I also appreciate Venerable and Mrs Alfred Bamigbose forS their hospitality when I was in Oyo. God will prosper everything you lay your hands on. R I expr EIesVs my appreciation to my fathers in the Lord for their prayers, Rt. Rev. Dr. Adewale. NA. Adebiyi, Ven. Samuel. A. O. Osungbeju, Rev Ogunniran, Rev. Olayioye, Rev. OjeniUyi. Your anointing shall continue to increase in Jesus name. Also to my principals: Mr. Akinola, Mr Adeogun, Mr. Owolabi, Mr Akinrinade and my colleagues: Alhajis Oseni, Tairu Morakinyo, Rufhai, Asipa and Mr Oshin. Pastors Akinyemi, Adeleye, Olujimi and Oladepo. More anointing in Jesus name. I am also very grateful to my brothers and sisters in the Lord at iv the Full Gospel Business Mens‟ Fellowship: Prof. Folami, Dr. and Mrs Adetola, Mr Tom-Tar, Mr Ubabukoh, Mr Bassey, Dr and Mrs Salami for their encouragement and prayers. Finally, I express my unreserved and profound appreciation to my family members most especially my uncle and father Mr. F. Olowoyeye, my cousin Mr. O. Ogedengbe, my hubby Mr O. A. Apara, my darling children: Engr. and Barr. A. Afolabi, Dr. O A. Apara, Barr. I. O. Apara, Miss. A. O. Apara and Mr. O. O. Apara for their support, prayers and encouragement. To my very special sister-in-law Mrs. A. Adio-Moses, our in-laws Asiwaju and Evang. Leke Afolabi and my very nice sisters: Mrs Akinola, Mrs Adeoti and Mrs Aladeejebi, I say a Rbig tYhank you. A R LI B AN BA D F I Y O T RS I IV E UN v CERTIFICATION I certify that this work was carried out by Mrs Ore-ofe Modupe Apara, in the International Centre for Educational Evaluation, Institute of Education, University of Ibadan. AR Y LIB R N A ------------------------------------------A----D------------------------- SuperIvBisor T. WF. Yoloye B.Ed, M.E dO,(Ibadan), Ph.D (Lagos) TProYfessor, Institute of Education, S I University of Ibadan, Nigeria. ER IV UN vi TABLE OF CONTENTS Page TITLE OF PROJECT i DEDICATION ii ABSTRACT iii Y ACKNOWLEDGEMENTS A R iv CERTIFICATION R vi TABLE OF CONTENTS I B vii LIST OF TABLES L x LIST OF FIGURES A N xii LIST OF APPENDICES D xiii LIST OF ABBREVIATIONS B A xv F I CHAPTER ONE: INTRODUCTION O 1 1.1 Background to the problem Y 1 1.2 Statement of the problemI T 13 1.3 Hypotheses S 14 1.4 Scope of the studyR 14 1.5 Significance oEf the study 15 1.6 DefinitioInV of terms 16 N CHAPUTER TWO: LITERATURE REVIEW 19 2.1 Theoretical Background 19 2.2 Conceptual Framework 22 2.3 Teaching Effectiveness in Science, Chemistry in Particular 23 2.4 Problem-Solving as an Inquiry-Base Instructional Strategy 34 vii 2.5 Problem-Solving Models 37 2.6 Students‟ Attitude to Science, Practical Chemistry in Particular 47 2.7 Achievement in Science, Practical Chemistry in Particular 50 2.8 Chemistry Process Skills and Students‟ Attitude to Science, Practical Chemistry in Particular 54 2 9 Chemistry Process Skills and Achievement in Science, Practical Chemistry in Particular 56 2.10 Class Size and Students‟ Attitude to Science, Practical Chemistry in Particular Y 58 2.11 Class Size and Achievement in Science, Practical Chemistry in Particular R 60 2.12 Appraisal of literature reviewed A 63 R CHAPTER THREE: METHODOLOGY I B 66 3.1 Research Design L 66 3.2 Factorial Design N 67 3.3 Variables in the study A 67 3.4 Population D 68 3.5 Sampling technique and Sample A 69 3.6 Instrumentation I B 70 3.7 Procedure for the Study F 73 3.8 Treatment Procedure O 73 3.9 Data Collection 79 3.10 Data Analysis I T Y 79 3.11 Methodological ChaSllenges 79 CHAPTER FOUR: R RESULTS AND DISCUSSION 80 4.1 Testing thVe HEypotheses 80 4.1.1 Ho1a MIain effect of treatments on students‟ attitude to practical chemistry 80 4.1.1 Ho1bN Main effect of treatments on students‟ achievement in practical chemistry 82 4.1.2 UHo2a Main effect of level of possession of chemistry process skills on students‟ attitude to practical chemistry 85 4.1.2 Ho2b Main effect of level of possession of chemistry process skills on students‟ achievement in practical chemistry 87 viii 4.1.3 Ho3a Main effect of class size on students‟ attitude to practical chemistry 89 4.1.3Ho3b Main effect of class size on students‟ achievement in practical chemistry 91 4.1.4 Ho4a Interaction effect of treatments and level of possession of chemistry process skill on students‟ attitude to practical chemistry 93 4.1.4 Ho4b Interaction effect of treatments and level of possession of chemistry process skills on students‟ achievement in practical chemistry 95 4.1.5 Ho5a Interaction effect of treatments and class size on students‟ attitude to practical Y chemistry R 97 4.1.5 Ho5b Interaction effect of treatments and class size on students‟ achievement Ain practical chemistry R 98 4.1.6 Ho6a Interaction effect of level of possession of chemistry process skIiBlls and class size on students‟ attitude to practical chemistry L 99 4.1.6 Ho6b Interaction effect of level of possession of chemistry pNrocess skill and class size on students‟ achievement in practical chemistry A 100 4.1.7 Ho7a Interaction effect of treatments, level of possesDsion of chemistry process skill and class size on students‟ attitude to prBactiAcal chemistry 102 4.1.7 Ho7b Interaction effect of treatments, leve l Iof possession of chemistry process skills and class size on students‟ achieveFment in practical chemistry 103 O CHAPTER FIVE: SUMMARY OYF F INDINGS, IMPLICATIONS AND RECOMIETNDATIONS 106 5.1 Summary of findiRngs S 106 5.2 Implications anEd Recommendations 108 5.3 LimitatioInsV and Suggestions for Further Research 110 ReferencNes 111 AppeUndices 129 ix LIST OF TABLES Page Table 1.1 Statistics of Entries and Results for May/June WASSCE (2000-2014) on Chemistry 4 Table 2.1 The eight problem types 35 Table 3.1: 3x2x2 Factorial Matrix 67 Table 3.2: The distribution of Public Senior Secondary Schools across the Eight RY Educational Zones in Oyo State A 68 Table 3.3: Sampling Distribution R 69 Table 3.4: Table of Specification I B 71 Table 4.1: Test of between sample ANCOVA for the effect of Treatments onL Students‟ attitude to practical chemistry N 81 Table 4.2: Estimated marginal means for Post student‟ attituAde to practical chemistry Score D 82 Table 4.3: Estimated marginal means for Post AchieAvement in Chemistry Score 83 Table 4.4: Test of between sample ANCOVA foIrB main effect of Treatment Groups on Post Chemistry Scores F 84 Table 4.5: Pairwise Comparisons Pos t OHoc Test on Treatment Groups and Control in Achievement in ChemYistry Score 85 Table 4.6: Pairwise CompariIsoTns Post Hoc Test on Treatment Groups and Control in AchievementS in chemistry Score Level of Significance 85 Table 4.7: EstimateRd marginal means for Chemistry Process Skills on Post Students‟ AttituEde to Practical Chemistry Score 86 Table 4.8: t-I tVest for Chemistry Process Skills against Post Students‟ Attitude to N Practical Chemistry Score 86 TableU 4.9: Estimated marginal means for Chemistry Process Skills for Post Achievement in Chemistry Score 87 Table 4.10a: Pairwise Comparisons Post Hoc Test on Chemistry Process Skills in post Achievement in Chemistry Score 88 Table 4.10b: Pairwise Comparisons Post Hoc Test on Chemistry Process Skills in post x Achievement in Chemistry Score Level of Significance 88 Table 4.11: t- test for Chemistry Process Skills against Post Achievement in Chemistry Score 89 Table 4.12: Estimated marginal means for Class Size for Post Students‟ Attitude to Practical Chemistry Score 90 Table 4.13: Estimated marginal means for Class Size for Post Achievement in Chemistry Score Y 92 Table 4.14a: Pairwise Comparisons Post Hoc Test on Class Size in post R Achievement in Chemistry Score A 92 Table 4.14b: Pairwise Comparisons Post Hoc Test on Class Size in post AchieveRment in Chemistry Score Level of Significance I B 92 Table 4.15: Estimated marginal means for Treatments and Chemistry PLrocess Skills for Post Students‟ Attitude to Practical Chemistry Score N 94 Table 4.16: Estimated marginal means for Treatments and ChAemistry Process Skills for Post Achievement in Chemistry Score D 96 Table 4.17: Estimated marginal means for TreatmentsA and Class Size for Post Students‟ Attitude to Practical Chemistry Sco rIeB 98 Table 4.18: Estimated marginal means for TFreatments and Class Size for Post Achievement in Chemistr yO Score 99 Table 4.19: Estimated marginal mYeans for Chemistry Process Skills and Class Size for Post Students‟ AIttTitude to Practical Chemistry Score 100 Table 4.20: Estimated maSrginal means for Chemistry Process Skills and Class Size for AchievemRent in Chemistry Score 101 Table 4.21: EstimEated marginal means for Treatment, Chemistry Process Skills and Class I SVize for Post Students‟ Attitude to Practical Chemistry Score 103 Table 4.22N: Estimated marginal means for Chemistry Process Skills and Class Size for U Achievement in Chemistry Score 104 Table 4.23: Between-Subject Factor 105 xi LIST OF FIGURES Page Figure 2.1: Conceptual Framework 22 Figure 2.2: Laboratory Problem Solving Model (LAPSOM) 40 Figure 2.3: Hands–On and Minds-On Problem-Solving Model (HAMPSOM) 45 Figure 4.1: Interaction of Treatment and Chemistry Process Skills on Students‟ Y Attitude Practical Chemistry Score R 95 Figure 4.2: Interaction of Treatment and Skill on Chemistry Achievement Test A 96 R LI B AN AD F I B O ITY S R VE UN I xii LIST OF APPENDICES Page Appendix IA: Laboratory Problem-Solving Model (LAPSOM) Instructional Guide of Nature of Matter 129 Appendix IB: Laboratory Problem-Solving Model (LAPSOM) Instructional Guide on Separation Techniques Y 132 Appendix 1C: Laboratory Problem-Solving Model (LAPSOM) Instructional GuideA on R Quantitative Analysis R 135 Appendix IIA: Hands-on and Minds-on Problem-Solving Model (HAMPSIOBM) Instructional Guide on Nature of Matter L 140 Appendix IIB: Hands-on and Mind-on Problem-Solving ModAel (NHAMPSOM) Instructional Guide on Separation TechniDques 143 Appendix IIC: Hands-on and Minds-on Problem-SolvAing Model (HAMPSOM) Instructional Guide on Quantita tIivBe Analysis 148 Appendix IIIA: Conventional Method (CONFTROL) Instructional Guide on Nature of Matter O 153 Appendix IIIB: Conventional MetYhod (CONTROL) Instructional Guide on Separation Techniques I T 155 Appendix IIIC: ConventioSnal Method (CONTROL) Instructional Guide on Quantitative AEnalyRsis 158 Appendix 1V:I V Answers to Questions in Appendices A 162 AppendixN V: Answers to Questions in Appendices B 163 AppenUdix V1: Answers to Question in the Appendices C 165 Appendix V11: Chemistry Achievement Test (CAT) Chemistry Achievement Test (CAT) 166 Appendix V111: Answers to the Chemistry Achievement Test 169 xiii Appendix 1X: Students‟ Attitude to Practical Chemistry Scale (SAPCS) 170 Appendix X: Question for the Chemistry Process Skill Rating Scale 172 Appendix X1: Chemistry Process Skills Rating Scale(CPSRS) 173 Appendix X11: Answer to the Questions on Chemistry Process Skills Rating Scale 176 Appendix X111: Laboratory Inventory Check List (LICL) 178 Appendix X1V: Photographs of Students Working in the Laboratory during the Y Research A R 180 BR I L AN D A F I B O SI TY VE R NI U xiv LIST OF ABBREVIATIONS FRN: Federal Republic of Nigeria FME: Federal Ministry of Education WAEC: West African Examination Council WASSCE: West African Senior Secondary Certificate Examination Y HAMPSOM: Hands-on and Minds-on Problem-Solving Model R LAPSOM: Laboratory Problem-Solving Model A LGAs: Local Government Areas R SAPCS: Students‟ Attitude to Practical Chemistry Scale IB CPSRS: Chemistry Process Skill Rating Scale L CAT: Chemistry Achievement Test N REPSOM: Researchers Experimental Problem-Solving MAodel NSSP: Nigerian Secondary School Science ProjeDcts LICL: Laboratory Inventory Check List A S.S.S: Senior Secondary Schools IB ANCOVA: Analysis of Covariance F O TY SI ER NI V U xv CHAPTER ONE 1.0 INTRODUCTION 1.1 Background to the Problem Science is probably the oldest course known by human beings, starting from agricultural science which is concerned with food production. This is one of the primary needs of man without which it is impossible for him to survive for a long time. Presently, science and technology have provided modern industries, satellites, computers, internet and have improved commuYnication drastically. Agriculture with biotechnology and genetic engineering have led to increRase in food production. Open heart surgery, test tube babies and organ transplant, housing witAh new building materials, architectural transformation of all kinds of dwellings and working placRes, public utilities, household gadgets and war weapons. These have caused great changes inL thIeB lives, outlook, attitude and habits of all mankind (Mokobia and Okoye, 2011; Adesoji an d Olatunbosun, 2008; Uko- Aviomoh, 2003). N Today, the economy and political strength of a nationA is judged by how much has been achieved through scientific and technological advancemenDt. Technology cannot thrive if science subjects are not encouraged in schools. Also the fuBtureAI development of any nation in the field of medicine, agriculture and engineering depends on how well science subjects are taught. It has been identified as an essential instrument for provFiding solution to socio economic problems such as hunger, poverty, unemployment, popul aOtion explosion and environmental degradation. Science became synonymous with survival Yand nations looked to science education answers to their problems (Afolabi, Oniyide and IATudu 2008; Eke, 2008). The Oxford AdvancedS Learner‟s Dictionary defines science as knowledge about experiments. Science is the studyE ofR problems found wherever we live, the finding of answers to specific questions which wVe formulate as facts, concepts, theories and laws which are recorded and passed on to posterNity. IHence science is an interwoven series of concepts, theories, facts and ideas that developeUd as a result of experimentation. Science education is defined in different ways: It is to improve critical thinking, logical responding and mainly to develop problem-solving abilities of the students (Dogru, 2008). It is concerned with the teaching and learning of science process and principles (FRN, 2004). It also involves training the learner to perform and observe experiment, analyze and interpret data (Eke 2008; Uko-Aviomoh, 2003). The need for indigenous technology and industrial development has made the Federal Government of Nigeria lay more emphasis on science education. The major aim of which is to improve students‟ ability to reason logically, think 16 critically and at the end solve problems that come their way in the environment (Orimogunje, 2008). Some of the goals of science education according to the National Policy on Education (FRN, 2004) are: To cultivate inquiring, knowing and rational mind for the conduct of a good life. Produce scientists for national development as well as, service studies in technology and the cause of technological development. Provide knowledge and understanding of the complexity of the physical world, the forms and the conduct of life. This means that effective science education does equip the learner with potentials and capabilities for self actualization (Ogunleye, 2008 and Mkpa, 2001). Chemistry is considered as both basic and applied science. When teachingR cheYmistry, teachers should emphasize both theories and experiments; Chemistry experiments plaAy an important role in teaching and serve as an ideal tool for combining theory and practice. ThRerefore, chemistry experiments should focus on learning goals and development of studIeBnts‟ laboratory skills, scientific reasoning skills, knowledge about experimental design, and c oLmprehensive ability. Many of the studies on students‟ learning effectiveness tend to focuNs more on knowledge learning effectiveness, learning retention, and migration on laboratory skAills (Shi-Jer, Hui-Chen, Ru-Chu and Kuo-Hung, 2012). D Any nation aspiring to be scientifically and tecAhnologically developed must have adequate level of Chemistry education (Eke, 2008). Chem iIstBry can be defined as the science of molecular behaviour. It deals with the composition, propFerties and uses of matter. It probes into the principles governing the changes that matter underOgoes (Ababio, 2011). Chemistry is all around us, it is ubiquitous in everything we do andY eve rywhere we go. For instance, we can see it in our food, appearance, medicine, house Tobjects, electricity, semiconductors, transportation and communication. Besides, CShemIistry is central to understanding of biological, environmental, physical, material and mRedical phenomena. No wonder the developed countries forged ahead by recognising and utilisEing the relevance of chemistry in their national economy (Ogunleye, 2008). ResearcIh Vevidences have shown that Chemistry‟s contribution to quality of life and nation building areN worthwhile in all aspects (Festus and Ekpete, 2012). Also at least a credit grade in ChemistUry is a pre-requisite for admission into Nigerian Universities for the study of biochemistry, pharmacy and medicine. The Federal Ministry of Education Chemistry curriculum (FME, 2007) has the following objectives;  To facilitate transition in the use of scientific concepts and techniques acquired in basic science and technology with Chemistry. 17  To provide the students with basic knowledge in chemical concepts and principles through efficient selection of content and sequencing.  To show Chemistry in its interrelationship with other subjects.  To show Chemistry in its link with industry, everyday life, benefits and hazards and  Provide a course which is complete for pupils not proceeding to higher education while it is at the same time a reasonably adequate foundation for post secondary Chemistry courses. The topics in the senior school Chemistry curriculum are arranged into instructionYal units and sequenced in spiral form with each unit treated in greater detail as the course progrResses. Each unit is organised under the following headings: teaching topics, performance objeActives, content, activities (teacher and students), teaching and learning materials and evalRuation guide. The curriculum stresses the importance of practical activities of the students toI eBnsure that learners are provided with continuous experience in skill of defining problems. Al sLo recognising assumptions, critical thinking, hypothesising, observing, collecting and recordiNng data, testing and evaluating evidence, manipulating variables, generalising and applying genAeralisations. In line with the current trends in chemical education, the teaching of chemistry fAocuDses on the following broad aims:  To stress principles and unifying IcBoncepts of chemistry without demanding memorization by pupils of a vast amou nt of factual information and  To develop skills in investigating pFroblems based on an understanding of practical work (WAEC Syllabus, 2014- 2016 )O. In implementing the curTricuYlum the document recognised some possible constraints such as ill equipped laboratories, lacIk of qualified teachers and large classes. Over the years students‟ performance in the subject hSas remained persistently low, discouraging and disturbing (Abudu and Gbadamosi, 2014; OgEunRleye, 2008; Odubunmi, 2006). Other researchers observed that the teaching of science in NigVerian secondary schools has encouraged memorization of facts, that teachers rely solely on leNcturIe method of teaching at the expense of other methods. As a result, learners were only givUen the opportunity to listen, record and regurgitate facts whenever necessary. This may be due to lack of understanding of the concepts by the teachers, lack of teaching materials and uncooperative attitudes of the students (Udogu, Ifeakor and Njelita, 2007; Ayogu, 2007; WAEC, 2007 and 2005). Ineffectiveness of science teachers (Berk, 2005). The methods used in teaching science in secondary schools do not help in the acquisition of science process skills by the students (Madu, 2004). Secondary school students often show negative attitude to chemistry (Festus and Ekpete, 2012). Other factors such as poor method of instruction, inadequate exposure to laboratory 18 activities (Nwagbo and Chukelu, 2012; WAEC, 2007), poor knowledge of separation techniques (WAEC, 2005) and lack of problem-solving abilities (WAEC, 2007; 2005). Also failure to read and understand the question before rushing to answer (WAEC, 2007), poor performance in practical chemistry (WAEC, 2012; 2007 and 2003) and poor quantitative skills (WAEC, 2005). Students‟ gender (Adesoji and Fasuyi, 2001), laboratory inadequacy (Adeyegbe, 2005), school type (Adesoji and Babatunde, 2002), teacher and school environment (Olatunbosun, 2006), all these have led to poor performance of students in West African Senior Secondary Certificate Examination (WASSCE) as shown in Table 1.1. Y Table 1.1 STATISTICS OF ENTRIES AND RESULTS FOR MAY/JUNE WASASCRE (2000- 2012) ON CHEMISTRY BRI TOTAL TOTAL TOTAL TOTA TOTAL A1-C6 D7 & YEAR A1-C6 D7 & E8 L FAILE FAILEENTRY L SAT SAT % % E8% D D % 2000 201369 195810 97.24 62442 31.89 52303N 26.71 81065 41.40 2001 311606 301740 96.83 109397 36.26 81A679 27.07 110664 36.67 2002 291372 287424 98.65 98988 34.42 AD88580 29.47 99856 36.09 2003 318324 304906 97.84 153839 50.B98 79448 24.26 71619 21.84 2004 345078 340774 98.07 128133 3I8.97 95404 26.83 117237 34.19 2005 338307 327225 98.20 13O5544F 37.35 84267 27.15 107414 35.50 2006 389315 375285 97.93 Y1 40263 38.65 89998 29.03 123204 32.32 2007 432230 422681 97.79T 194284 45.96 104680 24.76 111322 26.33 2008 428513 418423 9S7.6I4 185949 44.44 114697 27.41 110417 26.38 2009 478235 468546R 97.97 204725 43.69 114020 24.33 119260 25.45 2010 477573 465E643 97.50 236059 50.70 109944 23.61 98165 21.08 2011 575757 IV565692 98.25 280250 49.54 151627 26.80 129102 22.85 2012 64162N2 627302 97.77 270570 43.13 192773 30.73 148344 23. 65 2013 64U9524 639131 98.40 460470 72.05 95030 14.87 61340 9.60 2014 652809 644913 98.79 399062 61.88 142927 22.16 85461 13.25 Source: The West African Examinations Council (WAEC), Test Development Division, Ogba, Lagos. Table 1.1 reveals that students‟ performance in chemistry has been very poor, less than 50% of the students who sat for West African Senior Secondary Certificate Examination 19 (WASSCE) from year 2000-2012 had scores within grades A1-C6 except in years 2003 and 2010 where the percentages were slightly above 50% (50.98 and 50.70 respectively). There was a great improvement in year 2013 with the highest result, but another drop in percentage in year 2014. In Nigeria students who had scores within A1-C6 grade are considered for admission into the tertiary institutions. Therefore the percentage of students who sat for the West African Senior Secondary Certificate Examination (WASSCE) that were considered for admission is less than average (50%) in year 2000-2012, except in years 2003 and 2010. The highest number of students that were considered for admission was in 2013, but a reduction in percentage of these students in 2014. Failure in other science subjects has been reported by Ogundipe (2004) and OlatoRye Y(2002). Researches show that under achievement and low enrolment in chemistry and other sAciences are not limited to Nigeria, this is reported for other countries especially in physics andR chemistry (Wetzel (2008); Angrist, Lang and Oreopoules (2007); Stieff and Wilensky 2003). IB The poor performance of students has made science educators to foLcus on how to improve the teaching and learning of chemistry over the years (Adeyegbe, 2005N; Osokoya, 2002). They call for a new direction in science teaching being concerned about the sAtate of science education in Nigeria and the need for a radical approach. Adesoji (2008) and NDdioho (2007) suggested that one of the urgent needs in Nigeria is how to improve the teachinBg aAnd learning of science, that the condition of science teaching and learning in schools is ve ryI discouraging, it calls for all stakeholders in education to rise up to this challenge in the Finterest of national development. The teaching and learning of science need improvement. InO their contribution Akinbobola and Afolabi (2010) also suggested that for science teaching Yto b e meaningful and relevant, the nature of science must be adequately reflected. This calls fTor a shift of emphasis from the traditional content and factual acquisition of scientific knoSwleIdge to those that actively involve the learner in learning by doing. With the inauguration ofR the 6,3,3,4 system a new science curriculum was developed for secondary schools with greVaterE emphasis on laboratory activities and tailored towards an inquiry oriented science (FRN 2I004). However this has not solved the problem, population explosion, inadequate qualified teaNchers coupled with lack of laboratories or a well equipped laboratory and wrong method Uof instruction have worsened the situation (WAEC, 2007). Adane and Adams (2011) stressed the importance of practical Chemistry and wrote that students who are given opportunities to work with specimens, manuals and equipments during laboratory work are able to investigate scientific problems which make them understand theories and principles of science concepts better. Also the West African Senior Secondary Certificate Examination (WASSCE) consists of two papers: theory and practical. The practical is 50 marks. 20 This shows that the performance of students in the practical examination is very important since it can affect the overall performance of the students in the examination. It has been reported that the manner in which science subjects are taught in most of Nigerian secondary schools shows that majority of science teachers use the traditional lecture approach. Most science teachers do not encourage students‟ active participation in the teaching and learning process. There is also inadequate provision for practical activities and those provided are often inappropriate to produce the desired learning effects. Experiments in science subjects are often turned into demonstrations by the teachers for students to observe and to copy notes which involve drawing of diagrams where necessary (Abudu and Gbadamosi, 2014; Agbowuro 2008; Ndioho 2007). In order toR tryY to find solution to these problems because of the importance of practical chemistry, Athe researcher developed Hands-on and Minds-on Problem-Solving Model (HAMPSOM) aRnd established the extent to which this model and Laboratory Problem-Solving Model (LAPSOIBM) improved students‟ attitude to and achievement in practical chemistry. It further determin edL the moderating effects of chemistry process skills and class size. N In common language, a problem is an unpleasant sAituation, a difficulty. In Webster‟s Dictionary a problem is defined as “A question raise foAr inDquiry, consideration, or solution”. In a research situation, a problem arises when the researcher is faced with questions to which answers are not readily available, while a scientific proble mI Bis a question you do not know the answer to. A problem space is a mental representation of aF problem that includes the initial state and the goal state of the problem as well as the iOntermediate states attained when solving the problem (Taasoobishirazi and Glynn, 2009). YProblems occur in a situation where there is some obstacle between the given problem andI Tthe goal. The intervening obstacle or barrier or problem space requires planning, thinking aSnd channeling of thought towards finding a solution to the problem. According to BilRgin (2005), Problem-solving is the highest form of human activity hence the highest form oVf leEarning, and has been described as a method of learning. Several terms such as analytical, criticIal and reflective thinking, scientific method, discovery, inquiry, active learning and process baseNd have been used synonymously with problem-solving. According to Erinosho (2003) scientifiUc inquiry is the key to science learning and children can be helped to develop the required skills. Problem solving has been defined in several ways:  Problem solving means the application of already acquired knowledge of ordered science process skills (by the solver) to arrive at solution to novel and related chemical problems (Raimi, 2002) 21  Problem solving requires overcoming all the impediments in reaching a goal (Bilgin, 2005)  It is converting an actual current situation (the NOW- state) into a desired future situation (the GOAL-state). Whenever you are thinking creatively and critically about ways to increase the quality of life (or avoid a decrease in quality) you are actively involved in problem solving (Rusbult, 2008)  It improves students‟ ability to reason logically, think critically and at the end solve problems that come their way in the environment (Orimogunje 2008Y) Problem-solving is one of the most important issues in teaching and learning. RThe role of problem-solving in science is indispensable. It is an integral part of science. SciAence itself is a problem-solving subject. It is a subject that revolves around finding one solutRion or the other to some problems. Problem-solving can and should be the centre of the instruIcBtion, also the way it is practiced must change, it should be a part of an active learning of the iLnstructional process. When students know all the relevant facts and principles necessary for theN solution of a problem, they may be unable to solve it because they lack any systematic strategy Afor guiding them to apply such facts and principles (Gok and Silay, 2010). The notion of proAblemD-solving which is sometimes described as a core skill has received much attention in the literature of science education. Unfortunately there is considerable diversity in seeking to describe wIhBat problem-solving actually is, ranging from descriptions of analytical procedures to statemFents like „what you do when you don‟t know what to do (Rusbult, 2008). For this study prob lOem-solving is the application of acquired knowledge of ordered science process skills (by thYe solver) to arrive at solution to related problems in order to meet the present scientific and teIcThnological trend. There are several methods of studying problem- solving these include; InStrospection, behaviourism, simulation, computer, modeling and experiment. This study isR on modeling and experiment aspect of problem-solving. ConceptuVallyE, a problem solver (student) needs to possess relevant information and reasons with the relevaInt information to tackle the problem. In other words, problem-solving involves conscious anNd systematic application of acquired information and reasoning to overcome an event perceiveUd by an individual as problem. The problem solver is assisted during the experiments with varying degrees of hint, cues and clues. Problem-solving depends on what the solver knows and what he possesses at the time of solving the problem. Students must develop the ability to conduct science investigations using prior knowledge and experiences, along with treating science investigations as problem-solving (Wetzel, 2008). Problem-solving is very important for many subjects. Chemistry is no exception, combining in its problems characteristics of mathematics and 22 physics problems and adding its distinct chemical features (Cardellini, 2006). He further stated that as teachers we believe that working on problems is an effective way to learn, unfortunately, our students usually develop the attitude that arriving at the answer is more important than understanding the solving process. He explained that this is due in part to the way we teach problem-solving, usually when teaching we show them only some stages of the process, neglecting the analysis stage. This is so because as experts we are no longer able to recall the effort we had to expend the first time we tried to solve a problem, since it is now familiar to us. Also that from our presentation, students see a clean, even elegant solution, having little in common wYith the uncertainty and the fuzzy thinking that they experience when they try to solve Ra problem themselves. DeHaan, (2009) in his own contribution said that engaging learners in Athe excitement of science, helping them to discover the value of evidence-based reasoningR and higher order cognitive skills, and teaching them to become creative problem solvers hIaBve long been goals of science educator reformers. However the means to achieve these g oLals, especially methods to promote creative thinking in scientific problem-solving, have not Nbecome widely known or used. Hence this study used problem-solving strategy. A Attitude according to the Encyclopedia of EducatiDon is a predisposition to respond in a certain way to a person, an object, an event, a situaBtionA or an idea. An attitude towards something consists of a person‟s collection of facts about th eI subject, which may enable her to feel antipathy towards it, and manifest in either acceptance oFr avoidance of the subject. Oguntade (2000) defined attitude as the effective disposition of a peOrson or group of persons to display an action towards an object based on the belief that such aY person or groups of persons has about the object. According to Gonen and Basaran (2008), OIgTunkola (2002) and Yoloye (1994) the attitude of a learner towards science would determine thSe measure of the learners‟ attractiveness or repulsiveness to science. Rosemund (2006) wrotRe that attitude implies favourable or unfavourable evaluative reactions towards somethinVg, eEvents, programmes, etc exhibited in an individual‟s beliefs, feelings, emotions or intended behaIviours. ErdeNrmir (2009) indicated that attitudes are seen to be dynamic in nature and under constant change aUs they interact with behaviour and must be viewed in probabilistic rather than deterministic terms because of the complexity of structure of an attitudinal network. They stressed that attitudes cannot be observed directly, but inferred from what a person says or does, that attitude measurement has become a common part of research into school and schooling throughout the world. That attitude is assumed to have an affective component of how students were seen by peers and themselves. They offered some generalizations about attitudes: 23  Students tend to have positive attitude towards school and the subject matter taught at school at all grade level.  The attitude of students towards school and school subjects tend to become less favourable over their years at school.  Students tend to like certain subjects e.g. science, sports, reading more than others (e.g. mathematics, writing, agricultural science). Festus (2007) contended that performance appears generally to be the fundamental goal behind every life struggle, but the positive platform has consequential effects of improving the wortYh of the students and can only be achieved through acquisition of positive learning attitudeRs. That the attitude of a student triggers his behavior, and attitudes are antecedents which serAve as inputs or stimuli that trigger actions. R The issue of attitude towards chemistry and science in general is alsIoB a problem in England, Northern Ireland and Wales. Craker (2006) examined how young peLople‟s attitude to science affects their subject choice and achievement. They argued that Nthe introduction of compulsory science education to age 16 in England, Wales and Northern IreAland has not succeeded in changing the level of interest in science. Ishola (2000) attested to tDhe fact that success in problem-solving process depends not only upon the ability to masterB theA conceptual and procedural knowledge but also upon the affective characteristics of the pro bIlem-solver (student). That those with positive attitude towards instruction and subject contenFt are more likely to perform better than students with negative attitude. Several studies have bOeen reported in literature on the relationship between attitude toward problem-solving and Ystudents‟ performance. In a study on students‟ attempt to solve chemical problems, Frazer and ISTleet cited in Sule (2000) after analyzing seventy six sixth form students‟ solutions to the proSblems given, selected twenty two unsuccessful students for further in depth analysis. The reseRarchers found that seventy six percent of the unsuccessful students have negative attitude towEards problem-solving. Norman and Salleh (2006) indicated that students‟ attitude and inteIreVst could play a substantial role among pupils studying science. StuNdies show that most of the secondary school students often show negative attitude to chemistrUy which is associated with the poor performance in the subject in West African Senior Secondary Certificate Examination (WASSCE) (Festus and Ekpete, 2012; Adesoji,2008). In his own contribution Akubuiro (2004), asserted that students‟ attitude towards science subjects is positively related to their performance in these subjects, that attitude contributed substantially more than other variables in predicting achievement. A number of other studies on the relationship between students‟ attitude and learning outcome in science show that science educators have not 24 reached a consensus on the relationship between the two variables. Adesoji (2008); Goner and Basaran (2008) stated that conclusions from researches show that in order to increase the level of attitude and success in science education, new teaching methods and technology need to be implemented in science education. It is on these reports that the researcher developed a model known as Hands-on and Minds-on Problem-Solving Model (HAMPSOM) combining both theoretical and practical aspect of chemistry, which does not exist in literature but separate theoretical and separate practical models. She compared the effect(s) of this model with Laboratory Problem-Solving Model using the instructional guides on students‟ attitude to and achievement in practical chemistry. She assessed the level of chemistry process skills possessed by the sRtudeYnts and studied the effect of class size. Achievement is defined as „a thing that somebAody has done successfully, especially using their own effort and skill‟ (Oxford Advanced LearnRer‟s Dictionary pg 11). Gok and Silay (2010) discovered that when problem-solving achieIvBement of the students increases, the motivation and attitude of the students probably increases . LGonen and Basaran (2008) reported that students‟ positive attitude towards science probably Ncorrelate with their achievement in science. A Apart from the possible influence of treatmAentsD (independent variables) on students‟ attitude to and achievement in practical chemistry (dBependent variables), factors such as possession of chemistry process skills and class size were co nIsidered in this study. In literature not much work was seen on chemistry process skills and tFhe reports from the few researchers such as: poor quantitative skills, poor exposure to lab orOatory activities, poor performance in practical chemistry (Nwagbo and Chukelu, 2012; WAEYC, 2007 and 2005). These are some of the reasons why this study looked at possession of chIeTmistry process skills. Since the main focus of this study is to help students to acquire skills to Sarrive at solution to problems that come their way in the environment, also to meet the present Rscientific and technological trend. Class size as reported in literature was identified as one Vof thEe factors probably responsible for the problems discussed above and also one of the possible Iconstraints in implementing the senior secondary chemistry curriculum. Therefore the study looNked at class size as one of the moderating variables. PUerforming experiments and practical are integral part of chemistry lessons. Research studies have shown that students may achieve greatly when the teaching and learning of science occur in an environment where students are allowed to carry out investigations, not only in the aspect of understanding scientific concepts but also in acquiring scientific skills (Nwagbo and Chukelu, 2012). Adane and Adams (2011) also discovered that students who are given opportunities to work with specimens, manuals and equipments during laboratory work are able to investigate scientific 25 problems which make them understand theories and principles of science concepts better. Hands-on science education experiences may have lasting and personal effects on students (Hudson, 2007). Most secondary school teachers often pay little attention to practical work and laboratory activities as a very good way of promoting the learning of chemistry and also acquisition of appropriate skills (Millar, 2004). It has been observed that when practical is taught, teachers often neglect the teaching of the necessary practical skills (Agbowuro, 2008). Process of science refers to the practices used in science to uncover knowledge and interpret meaning of those theories (Carpi and Egger, 2009). While scientific method is aY way to ask and answer scientific questions by carrying out experiments and making observRations. The underlying skills and premises which govern the scientific method are referred to as Ascience process skills (referred to as chemistry process skills in this study) (Geek, 2012). SciencRe process skills are a set of broadly transferable abilities and potentials appropriate to science IdBiscipline and reflective of true behaviour of scientists (Okeke, Akusola and Okafor, 2004). W eLtzel (2008) discovered that problem-solving is the essence of scientific investigations, that it reNlies heavily on the effective use of the science process skills possessed by students to completAe an investigation. That the science process skills are the foundation of problem-solving inA scDience therefore they are also problem- solving skills. These skills are separated into two catBegories namely basic and integrated. The basic science process skills are: Observing, Classify inIg, Measuring, Communicating, Inferring and predicting. The integrated science process sFkills include: Experimenting and Interpreting data. There is a hierarchical relationship betw eOen the two broad skills the acquisition of basic skills is a pre-requisite for the acquisition of iYntegrated skills. This study will concentrate on most of basic skills such as measuring, obsIeTrving, inferring, predicting and the integrated skills such as experimenting and interpretiSng data. Problem-solvingR skill is one of the important goals of chemistry education any chemistry curriculum sets thVis sEkill as a criterion for any planned instruction to reach (Bilgin, 2005). In their own contributioIn Mahalingam, Schaefer and Morlino (2008) wrote that chemistry as a discipline involves proNblem-solving. They went further that lack of the requisite problem-solving skills in chemistrUy is an obstruction to doing well in the course. They added that the passive nature of a traditional question and answer recitation does not provide an adequate environment to develop these skills. Hence this study examined the extent to which Laboratory Problem-Solving Model ( LAPSOM) by Onwioduokit (1989) and Hands-on and Minds-on Problem-Solving Model (HAMPSOM) developed by the researcher using the instructional guides, involved the students in problem-solving through their influence on students‟ attitude to and achievement in practical 26 chemistry, compared the effects of the two model approaches through their interactions with the variables, assessed the level of possession of chemistry process skills by the students and the effects of class size. Step by step procedures of problem-solving are called scientific methods. Solving any problem scientifically involves several steps, which are constructed in form of model. Model involves the use of diagrams, concepts maps, graphs, pictures, physical models and other means to explain an investigation‟s findings (Wetzel, 2008). Several researchers in problem-solving process developed different theoretical context models which are based on step by step approach such as Klavir and Gorodetsky (2009) and Ishola (2000). Some researchers realising the imRportYance of practical in the science classes developed problem solving models in practicaAl (Laboratory) contexts these are Problem-Solving Model with eight steps by Wetzel (200R8); Inquiry Based Framework for Practical Problem-Solving Model with seven steps by IIgBe (2003); Laboratory Problem-Solving Model (LAPSOM) with five steps by Onwioduokit (1 9L89). Cardellini (2006) discovered that many models have beenN used in teaching but still the performance of the students is still low. Hence the reason Afor this study which involves the development of a combined theoretical and practical mAodeDl by the researcher which is Hands-on and Minds-on Problem Solving Model (HAMBPSOM), using problem-solving models by Selvaratnam and Frazer (1982) and Ikitde (1994 )I because of the unique nature of these models, incorporating intensive theoretical backgroFund and teacher guided discovery learning. The effectiveness of this model was comp aOred with that of Laboratory Problem Solving Model (LAPSOM) developed by OnwioduoYkit (1989), using the instructional guides for the two models. LAPSOM has its root in the scIieTnce approach models and in the philosophy of instrumentalism derived from John Dewey‟Ss pragmatic view. It facilitates student‟s development of skills in practical (Figure 2.2, pg R40). It is in two parts. The first part shows a general approach for solving practical problemVs, cEonsists of five procedural stages and eight action steps. The reversible nature of the procedurIe ensures cognitive and process flexibilities which are required at each stage for arriving at thNe problem objective. The second part is concerned with how students are taught to use the systeUmatic approach. This is the Instructional Guide. Hands-on and Minds-on Problem Solving Model (HAMPSOM) developed by the researcher (Figure 2.3, pg 45), is sequential, hierarchical and reversible. It is useful for acquisition of knowledge and the development of laboratory skills in practical and fosters experimental proficiency of students, where they have to raise questions about what to do with the apparatus and materials presented to them. It is in two parts, the first part is the approach for teaching the skills 27 with five procedural stages and eleven action steps. The second part is concerned with how teachers and students use the systematic approach in problem-solving which is the Instructional Guide. An advantage of this model is that it can also be used for non experimental studies. This involves moving from stage 1B (Acquiring related theory) to stage 2A (Recalling theory) to stage 3B (Recording Data). Averett and Mclennan, (2011) and Ogundipe (2004), discovered another problem which is over population of students in the classrooms. This is as a result of population explosion arising from free education policy of Government in 1979. That the effect of this is that some classes contained as many as sixty eight (68) students who were therefore denied the individuRal oYr group attention that would have been beneficial to them. That a small group is describedA as that having few teachers with small pools of talent, often with limited range of subjects anRd characteristically finding it hard to justify costly investments on libraries, their pupils lack cIoBmpetition and interact with relatively few peers as they get stuck with same teachers for an Lentire school career. They explained further that large class size, on the other hand, is not Nconducive for serious academic work students may suffer discipline problems as teachers cannAot get to know their students easily. Teachers may not find it easy to stream students accorAdinDg to their ability, while commitment to work may stand the test of time. The National Policy on Education (FRN , I2B004) stipulates that the minimum number of students in a class in the secondary school is fForty (40). This formed the basis for the classification of class size in this study which is forty (O40) students and below constitute small class size, while forty one (41) students and above conYstitute large class size. IT 1.2 Statement of the ProSblem Learning isR an active, constructive, cummulative and goal-oriented process that involves problemV-soElving. Researches show that students need problem-solving skills to solve problems succesIsfully. The extent to which the students are involved in problem-solving and the possession Nof problem-solving skills are necessary for the students to perform well in the examinaUtions and to meet the scientific and technological trend in Nigeria. Researches show that the majority of science teachers use the traditional lecture method which does not encourage students‟ active participation in the teaching-learning processes. There is also inadequate provision for practical activities. Experiments are often turned into demonstrations for students to observe, to copy notes and draw diagrams during chemistry lessons. These and other factors have led to poor performance of students in chemistry in WASSCE. 28 In view of the above there is need to improve the teaching and learning of chemistry in order to improve students‟ problem-solving attitude and achievement for better performance in WASSCE. In an effort to seek for solution to this problem, the researcher developed a model Hands-on and Minds-on Problem-Solving Model (HAMPSOM) which combines both theoretical and practical aspects of science as opposed to the separate theoretical and practical models found in literature, incorporating intensive theoretical background and teacher guided discovery learning. This study therefore examined the extent to which the models (HAMPSOM) and Laboratory Problem-Solving Model (LAPSOM) using the instructional guides improved students‟ attitude to and achievement in practical chemistry. It further determined the moderating effects Rof Ylevel of possession of chemistry process skills by the students and class size. RA B N LI 1.3 Hypotheses Ho1: There is no significant main effect of treatmentsA on students‟ a attitude to practical chemistry. D b achievement in practical chemistrAy. Ho2: There is no significant main effec tI oBf level of possession of chemistry process skills on students‟ F a attitude to practicalO chemistry. b achievement iYn pr actical chemistry. Ho3: There is no sigIniTficant main effect of class size on students‟ a attitudSe to practical chemistry. b acRhievement in practical chemistry. Ho4: TVherEe is no significant interaction effect of treatments and level of possession I of chemistry process skills on students‟ N a attitude to practical chemistry. U b achievement in practical chemistry. Ho5: There is no significant interaction effect of treatments and class size on students‟ a attitude to practical chemistry. b achievement in practical chemistry. Ho6: There is no significant interaction effect of level of possession of chemistry process skills and class size on students‟ 29 a attitude to practical chemistry. b achievement in practical chemistry. Ho7: There is no significant interaction effect of treatments, level of possession of chemistry process skills and class size on students‟ a attitude to practical chemistry. b achievement in practical chemistry. 1.4 Scope of the Study This study involved practical oriented teaching with experiments incorporatinRg inYtensive theoretical background and teacher guided discovery learning using two pAroblem-solving models (LAPSOM and HAMPSOM) and control instructional guidesR. From the eight educational zones in Oyo state, three were randomly selected from IIBbadan and Oyo towns these are Ibadan city, Ibadan less city and Oyo. Three Local Gov erLnment Areas (LGAs) were chosen from the selected zones making nine LGAs namely IbNadan North, Ibadan North West, Ibadan South West, Akinyele, Egbeda, Oluyole, Atiba, AAfijio and Oyo East. Nine public senior secondary schools were randomly chosen fromD the selected LGAs. Nine intact classes of 359 chemistry students of Senior SecondaBry tAwo (S.S 2) participated in the study. The topics investigated are: I  Nature of matter: physical andF chemical changes, elements, compounds, mixtures and determination of the e mOpirical formula of magnesium oxide.  Separation techniqueYs: Sublimation, Filtration, Evaporation, Separating funnel method. IT  Volumetric anSalysis (Quantitative analysis). The main and interaRction effects of treatment, level of possession of chemistry process skills and class sizeV on Ethe dependent variables were investigated. 1.5 SUignN I ificance of the Study Teaching of problem-solving skills has often been a neglected aspect of chemistry instruction by teachers at the secondary school level. These have led to poor acquisition of problem-solving skills through performance of practical and experiments by the students as well as poor handling of problems. It is therefore hoped that, the result of the study could provide information on the effect of treatments on students‟ exposure and possession of chemistry process skills to solve 30 problems in chemistry. It may confirm the effectiveness or otherwise of the use of practical oriented teaching approach of problem-solving in the teaching and learning of chemistry. It could show which of the two models used is more effective on students‟ attitude to and achievement in practical chemistry. Furthermore, the result of this study in all possible interaction of the independent variables could provide the empirical basis for planning and executing a more effective technique of teaching chemistry aimed at improving students‟ performance in the subject in the cognitive, psychomotor and affective domain. It is hoped that it may consequently have a lot of implications for the aspect of chemistry education dealing with curriculum plannRing, Yteacher training as well as classroom practices. A Finally it could add to the pool of knowledge in the area of improvinRg the teaching and learning of chemistry at the Senior Secondary School level through tIhBe use of HAMPSOM, thereby improving the performance of the students in WASSCE. T hiLs may increase the number of students that will enroll for the sciences in higher institutionsN of learning. This is beneficial to the society because there could be increased manpower inA chemistry related fields, leading to improved health, agriculture and other services. D A 1.6 Definition of Terms. IB Operational Definition of Terms F Problem Solving Model: This is aO framework which shows the different stages a learner is expected to go through, from the Yproblem state to solution state. T Laboratory ProblemS SoIlving Model (LAPSOM): This is a model which consists of five procedural stages andR eight action steps. It involves students carrying out activities without the guidance of Vthe Eteacher. The stages are: Stage 1: Recognize the problem, Stage 2A: Reviewing iInformation. Stage 2B: Predict tentatively. Stage 2C: Draw up table for data. Stage 3A: ConNducting experiment. Stage 3B: Predicting from data. Stage 4A: Analyze the data. StagUe 5: Reviewing. Hands-on: This is used to describe the fact that students need to perform activities that create opportunities for them to interact with the apparatus (manipulation). 31 Minds-on: This involves presenting students with challenging situations where they have to raise questions about what to do with the apparatus and materials presented to them. Hands-on and Minds-on Problem Solving Model (HAMPSOM): This is a model which consists of five procedural stages and eleven action steps. It involves students carrying out activities and to think critically about what they are doing and ask questions which the teacher provides answers to. The stages are: Stage 1A: Problem Perception Stage 1B: Acquiring Related Theory. Stage 1C: Planning Experiment. Stage 2A: Recalling Theory and Making Tables. Stage 2B: Performing Experiment. Stage 3A: Observation. Stage 3B: Collecting and RecoRrdinYg Data. Stage 4A: Analysing Result. Stage 4B: Interpreting, Predicting data and drawiAng conclusion. Stages 5A: Evaluation of results and methods. Stage 5B: Consolidating KnowRledge Gained and Change in Technique. They may change method or quantities to observe the o LIB utcome. Problem-Solving Instructional Guide: This is the actual Nmethod of instruction which the teacher and the students undergo during the administration of Athe treatments and control. For this study, Laboratory Problem-Solving Model (LAPSOM), HaDnds-on and Minds-on Problem-Solving Model (HAMPSOM) and Conventional Method (conBtrolA) instructional guides were used. I Science Process Skills referred to as CFhemistry Process Skills in this study: These are the various skills the learners acquire durin gO the administration of the treatments and control. These skills are separated into two categoYries namely, basic and integrated. The basic science process skills are: Observing, ClassifyIinTg, Measuring, Communicating, Inferring and predicting. The integrated science process skSills include: Experimenting and Interpreting data. Level of possessioRn of Chemistry Process Skills: These are the level at which the students acquire these difVfereEnt skills. They are measured using Chemistry Process Skill Rating Scale (CPSRS) pre anId post. N ChUemistry Achievement: This is the students‟ scores in the pretest and posttest Chemistry Achievement Test (CAT) from Nature of matter, Separation techniques, Volumetric analysis (Quantitative analysis). Students’ Attitude to Practical Chemistry: This is the students‟ scores derived from Students‟ Attitude to Practical Chemistry Scale (SAPCS). 32 Learning Outcomes: These refer to the scores obtained by students in the chemistry achievement test and Students‟ Attitude to Practical Chemistry Scale after their exposure to the treatments and the conventional method. Class Size: This is the number of students in the class Small Class size: This is a class with a maximum of 40 students. Large Class Size: This is a class with more than 40 students. RY Conceptual Definition of Terms A Problem-Solving: This is the application of acquired knowledge of orderRed science process skills by the problem-solver (student) to arrive at solution to related probleImBs in order to meet the present scientific and technological trend. L N Introspection: This is the careful examination of one‟s thAought, feeling and reasons for behaving in a particular manner. D Simulation: A situation in which a particular sBet oAf conditions is created artificially in order to study or experience processes that could exist inI reality. F Behaviourism: The theory that all huOman behaviour is learnt by adapting to outside conditions and that learning is not inYflu enced by thoughts or feelings. T Modeling: The work ofS maIking a simple description of a system or a process that can be used to explain it. ER Practical: IAV lesson or an examination in science or technology in which students have to do or make thNings not just read or write about them. U 33 Y AR RIB L AN AD IB CHAOPFTER TWO Y 2.0 LIITTERATURE REVIEW The review of related literatuSre is highlighted in this chapter as follows: 2.1 Theoretical BackgRround 2.2 ConceptualV FraEmework 2.3 Teaching IEffectiveness in Science and Practical Chemistry 2.4 ProbleNm-Solving as an Inquiry-Based Instructional Strategy 2.5 PrUoblem-Solving Models 2.6 Students‟ Attitude to Science and Practical Chemistry 2.7 Achievement in Science and Practical Chemistry 2.8 Chemistry Process Skills and Students‟ Attitude to Science and Practical Chemistry 2 9 Chemistry Process Skills and Achievement in Science and Practical Chemistry 2.10 Class Size and Students‟ Attitude to Science and Practical Chemistry 34 2.11 Class Size and Achievement in Science and Practical Chemistry 2.12 Appraisal of literature reviewed 2.1 Theoretical Background The present study is conceived on the basis of some psychological learning theories that are considered relevant to the teaching and learning of science, and which are connected to problem- solving acquisition of practical skills and learning of science practical in general. Reforms movement in Science Education emphasize the role of the learner as self directed, cYritically reflective, creatively involved in theory building, testing and cooperatively engaged wiRth others in dialogue and discovery. This has been recommended as a way of enhancing learninAg in science by way of making its teaching more real and in line with the spirit of “what scieRntists do” (Cimer, 2007; Hudson, 2007). This is because teaching of science through expIeBriments and practical activities enable learners‟ to gain in depth knowledge of what is being tLaught. This line of thought conforms with the practical activity and experimental aspectsN of this study; which include enhancing science learning through hand- on activities. ExperimAents and practical activities involve such skills as manipulation of laboratory equipment, oAbseDrving, measuring, classifying, inferring, hypothesising. It also requires the application of tBhe knowledge of learned concepts, laws and theories to real concrete situations. The theories o fI Piaget and Gagne would provide the theoretical framework for this study. F Piaget’s Theory of Human Cognitive D eOvelopment. Piaget (1978)‟s, theory of humanY developmental psychology is of relevance to this study as it provides explanation for the dIevTelopment of students‟ mental structures which are capable of influencing learning and undSerstanding. He believed that human development has four stages, each one of the stages buildinRg on the previous one. The ability of a child to use symbols and think in an abstract manner VincrEeases with each subsequent stage until he is able to manipulate abstract concepts. He emIphasized that a child is most likely to attain full intellectual development at the formal operNational stage during early adolescence. At this stage, the child‟s thought process becomesU orderly and reasonably well integrated. He is able to understand and transfer understanding from one situation to another. His orientation to problem solving becomes distinct. The child is able to deal with a problem by gathering all relevant information and then making all possible combinations of the variables that can be employed in solving problems through the processes which form the building block of problem-solving model. 35 The learner is trained on how to solve problems by proceeding in a logical step by step sequence without skipping any step in the learning process. This means that whatever new concepts that is presented to the learner, there must have been concepts that are pre-requisites to that new knowledge in order for the learner to solve existing problem. Piaget believed that the knowledge of a particular capability would be a pre-requisite for a much higher capability for instance some concepts such as mole concept are pre-requisites for solving problems in volumetric analysis. That learning is through activity and experience, which could be used to explain the use of laboratory teaching strategy and experimental demonstration in this study, because the learners‟ concept of quantity, time, space, conservation and reversibility have developed, logical processRes Ysuch as observing, describing, classifying and measuring real objects can take place. The appAlication of this to practical teaching is necessary in that students should be assisted and helpRed to explore and interact with their environment as they are observing things around them. IItB is therefore necessary to allow students to interact with concrete materials so that the sk ilLls involved in measuring, observing, manipulating and in handling concrete materials can beN developed. The knowledge of Piaget‟s theory enables teachers assess the level of students‟ coAgnitive development and helps them formulate teaching strategies that are most appropriaAte iDn dealing with the students‟ problem-solving difficulties and to match curriculum with theB abilities of the learners. The knowledge of this theory tremendously assisted the researcher in the cIourse of this study. OF Y Gagne’s Theory of HierarchicalT Task and Instructional Strategy The problem-solvinSg inIstructional strategies used for this study are based on Gagne (1977) theory of hierarchical taRsk. His theory assumes that any piece of knowledge can be acquired by students who posVsessE certain pre- requisite knowledge. According to this theory, prior knowledge determines whaIt further learning that may take place. He believes that meaningfulness of instructionalN materials can be achieved through movement from concrete materials to abstract that is, learnUing should be sequentially structured by the teacher. He advocated for the breaking of task into a sequence of steps which are arranged in hierarchy. The theory of hierarchical learning is adopted in problem solving where a learner progresses from one step to another following the steps and strategies in the problem-solving model in which the success in one step determines the success of the next. 36 The problem-solving instructional guide drawn from the two models used in this study were based on Gagne‟s theory of instructional strategy which enunciated the elements of the components guiding the development of an instructional strategy. These elements guided the choice of steps built into the instructional guides. The instructional strategy based on Gagne‟s theory begins with the teacher asking questions/ problem statements as in step 1A (Recognition of problem). This is followed by bits and pieces of knowledge or operations needed by the students to carry out activities that will enable them to acquire the desired body of knowledge to solve the problem, which are steps 1B, 1C and 2A (Gathering and processing information). The related theory which is the information has to be recalled before solution is arrived at. This is followed by taskR anaYlysis as in steps 2B, 3 and 4 (Experimentation and Analysis of results). Evaluation follAows when the learning hierarchy is completed which could be in form of diagnostic test (step 5)R. Lastly the need for pre-requisite concepts in order to be able toI Bunderstand the higher concepts in a learning hierarchy was emphasized by the two theorists. N L A AD IB F O ITY S 2.2 Conceptual FrameRwork V E Creating Groups I N ExperimUental Group1(E1) Experimental Group 2(E2) Control Group(C) Pre Test Chemistry Achievement Test (CAT) 37 Students‟ Attitude to Practical Chemistry Scale (SAPCS) Chemistry Process Skills Rating Scale (CPSRS) Application of Treatments E1 E2 C RY Laboratory Problem-Solving Hands-on and Minds-on Problem-Solving ConveAntional Method Model (LAPSOM) Model (HAMPSOM) R (CONTROL) Instructional Guide Instructional Guide I BInstructional Guide L Nature of Matter. Determination Nature of Matter. N Nature of Matter. Of the Empirical Formula of Determination of the A Determination of the Magnesium Oxide. Separation Empirical Formula of D Empirical Formula of Techniques and Volumetric Magnesium OxidBe. SAeparation Magnesium Oxide. Analysis Techniques an dI Volumetric Separation Techniques Analysis F and Volumetric Analysis O Y I T Post Test S Figure 2.1: Conceptual RFramework E 2.3 Teaching EIfVfectiveness in Science and Practical Chemistry TNeaching effectiveness is the extent to which students‟ performance improve after a period oUf instruction in a manner consistent with the goals of instruction. This means that teachers are said to be effective when their teaching can lead to students‟ learning. It is therefore defined as a purposeful activity carried out by someone with a specialized knowledge in a skillful way to enhance the cognitive, affective and psychomotor development of a person or group of persons (Abudu and Gbadamosi, 2014; Olatoye ,2002). This means that it can be referred to as the ability of teachers to assist students achieve the desired educational outcomes through various approaches. 38 The difficulties in defining effective science teaching are embedded in the numerous characteristics and roles of the classroom teacher. It is generally accepted by researchers and educators for example Loughran, Mulhall, and Berry, (2004); Hattie, (2003) that effective science teaching requires an understanding of the subject matter, which needs to be taught in engaging ways. There is also empirical research and scholarly debate about what constitutes effective learning. Some of these theories include authentic learning (Herrington and Oliver, 2000), constructivism and social cognitive theory of learning (Vygotsky and Bandura, cited by Hudson, 2007). A teacher‟s unpretentious, caring nature can motivate students to work to their fullest potential (Alder, 2002; Easton, 2002). RY Cimer (2007) summarised some of the main principles of effective teachinAg in science as follows: R  dealing with students' existing ideas and conceptions, IB  encouraging students to apply new concepts or skills into Ldifferent contexts,  encouraging students‟ participation in lessons, N  encouraging students‟ inquiry and A  offering continuous assessment and providinDg corrective feedback, He discussed these principles in terms of their conItBribu Ation to effective teaching, and to students‟ learning in science. Dealing with Students’ Existing Ideas andF Conceptions Determining students‟ existing idea sO and conceptions has been recognised as an important variable in science teaching and a nYecessary part of teaching strategies. He discussed the role of students‟ existing ideas and coInTceptions in terms of learning and teaching science and then, described how to identify thSese ideas and conceptions. Finally, he presented ways to change these ideas and conceptions in Rorder to help students learn science meaningfully. Tytler (200V2); EHipkins, Bolstad, Baker, Jones, Barker, Bell, Coll, Cooper, Forret, France, Haigh, Harlow aInd Taylor (2002) argued that teaching science is effective when students‟ existing ideas, vaUlueNs and beliefs, which they bring to a lesson, are elicited, addressed and linked to their classroom experiences at the beginning of a teaching programme. That there is a common belief that students do not arrive in the classroom as empty vessels into which new ideas can be poured by teachers. They can have prior ideas and conceptions about the events and phenomena in the world around them, which might well be different from those intended by the teacher and scientific community. That meaningful learning occurs as students consciously and explicitly link their new knowledge to existing knowledge structure. This implies that effective instructional approaches 39 have to be based on what is already known by the learner. Therefore, the diagnosis of learners‟ pre- existing knowledge is important for teachers in order to plan subsequent teaching activities and help students link the new material to what they already know. Also determining students‟ existing ideas and conceptions in science may increase students‟ awareness of them, which is necessary for meaningful learning. When students become aware of their previously tacit ideas, they have a chance to compare them with scientific ones and change if necessary. In addition, determining students‟ pre-existing ideas and conceptions also help teachers confront any alternative ideas or misconceptions students may have at an early stage in the learning process so that these do not hinder students‟ learning (Cimer, 2007). RY Through determining students‟ existing conceptions, teachers can develoAp appropriate instructional strategies that move these unscientific ideas and conceptions towaRrds scientific ones (Hipkins et al, 2002). However, it is noteworthy that there is research IeBvidence that students‟ alternative conceptions are difficult to shift, and can offer a serious bLarrier to effective teaching (Tytler, 2002). Hipkins et al (2002) indicated that when teachersN take into account and build on students‟ existing ideas, experiences, and values, science educaAtion can become more inclusive for students from diverse cultures, girls and boys, students wDith special needs and special abilities. They explained that in order to determine students‟ exAisting ideas and conceptions, the literature reported a wide range of instructional method s IaBnd activities that teachers can use, such as reviewing previous work and stating goals, quFestion-and-answer, group discussions, brainstorming and debating ideas, providing examples,O and conducting experiments. In addition, students also need positive supportive learning envYiron ment where they feel comfortable and confident enough to disclose their existing ideas and IthToughts (Bell and Cowie, 2001). Teaching strategies sShape the learning environment. As part of the lesson design, an effective teacher selectsR a particular teaching strategy or set of strategies to engage students in learning. There aVre tEeaching strategies that can be transferred from one subject to the next. There are also strategIies that are more specific to a subject area. Generic teaching strategies include models for Nlearning, and specific science teaching strategies. All these strategies can be used to enhanceU the teaching and learning of science, and a teacher‟s affective domain appears towards the top of the list. When considering teaching strategies, experienced teachers understand the powerful influence of the teacher‟s affective domain. This domain includes the teacher‟s emotions, motivations, attitudes, and values. A teacher who displays enthusiasm for teaching science demonstrates positive emotions about science, which can influence students‟ attitudes. “I have noted time and time again how the teacher‟s affective domain can inspire or dampen students‟ 40 interests in a subject, and I‟ve also noticed this with my own children. For example, my son gained a love of science in Year 7, which he attributed to the highly-motivated teacher; yet in Year 8 he “hated” science, which he also linked to the teacher‟s attitude”. The teacher‟s affective domain can make the difference! (Hudson, 2007). Teachers generally enter the profession to “make a difference” to students‟ lives (Neal, McCray and Webb-Johnson, 2001). Knobloch (2003) stated that effective teachers who make a difference in the lives of their students are likely to be affectively motivated and caring teachers. Teaching methods such as presenting information to students directly from textbooks, providing demonstrations and activities without helping students to focus on the patteRrns Ythat are similar in the activities, or providing a discovery-oriented lesson without specificalAly relating it to prior knowledge, on the other hand, may not be successful in helping studeRnts to reveal their existing ideas. Briefly reviewing previous work at the start of a lesson by exIpBlicitly stating the goals of the current lesson activates students‟ existing ideas and conceptions rLegarding the new topic and helps retrieve previous learning. This helps students to be prepaNred for understanding the new material. The question-and-answer method is one of the most Acommon methods used by teachers for this purpose (Amos, 2002). Questions, especially oApenD-ended ones, can stimulate students to expose their informal and perhaps distorted precoBnceptions developed through their everyday experiences to facilitate their recalling ideas from thIeir long-term memory (Cimer, 2007). Sunal and Sunal (2002) emphasised tFhat the important point is to help students retrieve as many related experiences, ideas or skills Ofrom their long-term memory as possible. Retrieval from long-term memory alone is not enoYugh for meaningful learning to occur. Students also need to change their own understandingIsT of science into ones consistent with the scientific view (Alsop, Gould and Watts, 2002). StuSdents do not change their ideas or conceptions easily but they change them only if they see thRat the more scientifically valid ideas make sense to them and are more fruitful than theirV owEn in explaining a phenomenon and making predictions. Therefore, in order for change to occurI students must become dissatisfied with their existing knowledge and be aware of that there mNay be inconsistencies in their way of viewing the world. This requires a direct contrast betweenU their existing ideas and intended scientific views. They need to test and develop their models and thought processes in familiar contexts, which they believe are real, representative of everyday experience and under their control. Once they can see that current ideas or conceptions are no longer relevant to solve problems then new learning occurs (Cimer, 2007). Various strategies are suggested for teachers to use to challenge students‟ existing ideas. For example, peer interactions can be a valuable strategy by creating productive discussions. In such 41 instances, students experience dissatisfaction with their existing concepts, develop plausible new concepts and see the relevance of new knowledge in different contexts. Furthermore, conducting investigations or inquiry can also strongly challenge students‟ existing ideas. They can apply their own ideas, observe the process, make predictions about the results and record the results of the experiment. When they achieve unexpected results or find that others disagree with their interpretations or see that their current ideas will not solve the new problem, their existing conceptions are challenged. As a result, they come to the understanding that they should either modify or discard these old ideas and construct new ones (Goodrum; Hackling and Rennie, 2001). Similarly, simulations in combination with practical work can be effective in helpiRng sYtudents change their non-scientific conceptions (Peat and Fernandez, 2000). After determAining students‟ existing ideas and conceptions and making students aware of them, teachersR need to introduce scientific concepts to help them construct new knowledge (Glenn, 2001). IB This explanation phase should be clear and short, and allow time Lfor students to process new information and restructure their understanding. As learners‟ workNing memory, where they process information, is small, it takes at least five seconds to organise Aa 'chunk' of new information and to transfer it to long-term memory. Since the flow of theA mDaterial during a class is typically much faster, the student‟s short-term memory is quickly ovBerloaded and learning stops until a space is available in the short-term memory. As a re sIult, students cannot always process the new information rapidly enough because they migFht lose attention and thus, start daydreaming or not paying attention in the lessons (Cimer, 2 0O07). This is evidenced by research that indicates students retain 70 percent of the information dYuring the first ten minutes of a lecture, but only 20 percent of the last 10 minutes, students' effIeTctive attention is 25-30 minutes. All these, therefore, suggest that teachers should give short bSreaks or provide examples for students to process new information in their working memory. WRhen there is no new information coming, students can digest what is being said more readilyV. HoEwever, teachers should not rely on lectures too much for introducing new knowledge and Iskills because, as a traditional teaching method, lecturing can make students passive in the lessonNs, leaving too little time for them to process the new information. A strictly lecture- based prUesentation of facts and concepts may lead students to believe that everything has been figured out already and in order to pass their examination they must memorise facts and concepts instead of trying to understand them. In explaining new concepts or ideas, there are two important conditions that teachers should consider: creating attention in students and providing examples and opportunities for students to practise their ideas (Parkinson, 2004). 42 In order for students to comprehend new ideas or concepts and construct their own knowledge, they need to see clear examples of what the new ideas or skills represent. Furthermore, in learning new materials or skills, students should be given extensive opportunity to manipulate the environment (Joyce, Weil and Calhoun, 2000) as, according to Piaget (1978), students‟ cognitive structures will grow only when they initiate their own learning experiences. For example, Cimer (2007) suggested that teachers should provide tasks where students can engage in cognitive processing activities of organising, reviewing, rehearsing, summarising, comparing, and contrasting with other students, or with the teacher or working alone. In addition he wrote that teachers should encourage informal discussions and structure science activities so that students are RrequYired to explain and justify their understanding, argue from the data, justify their conclusionAs and critically assess the scientific explanations of a matter. He also suggested that teachers canR demonstrate skills and work on a problem on the board whilst discussing it. IB If the concepts taught at school are not related to students‟ everyd aLy lives, they may fail to use them adequately outside the school. Thus, their knowledge may Nremain in the form of acquired isolated knowledge 'packages'. Effective learning requires Astudents to apply newly acquired concepts or skills to different contexts (Cimer, 2007). He Dwrote further that as a result, they can achieve higher learning outcomes and use their knoBwleAdge or skills to solve the problems in their everyday life. For these reasons, teachers should cIreate opportunities that allow students to apply their knowledge to real life situations. He suggFested that teachers should: …….identify practical applications of co nOcepts, use practical experiences and applications to make connections between concepts and „real world‟ experiences in ways that enrich understanding of conYcepts, and show how knowledge of one set of concepts forms the foundation foIrT learning about other concepts (p 313) He suggested that teacheRrs cSan employ various methods to help students to apply their knowledge, such as conducting prEactical work, field trips, simulations, writing activities and role-play. Following IisV a brief discussion of some of these methods drawn from the literature. A uNseful method for enabling students to participate in the learning process is to conduct practicalU work. The important point in doing practical work is to ensure that students are mentally active. It can provide a good opportunity for students to apply their newly acquired knowledge or skills and gain first-hand experience of phenomena talked about in theory (Millar, 2004; Amos and Boohan, 2002). When students engage in practical work, they can test, rethink and reconstruct their ideas and thoughts. For these reasons, many studies reported that practical work improved students‟ learning and understanding (Millar, 2004; Dave, 2003). Dave (2003) argued that such positive outcomes may be as a result of students‟ gaining ownership over the concepts they learn as they 43 'discover' the knowledge themselves during practical work. Hands-on science education experiences can have lasting and personal effects on students (Hudson, 2007). In relation to practical work, simulations can be used to replace laboratory work when it cannot be done in schools (Peat and Fernandez, 2000). So, they can help students understand invisible conceptual worlds of science through animation, which can lead to more abstract understanding of scientific concepts. Students can understand not only just what happens, but also how and why. Using simulations in science lessons also improve students‟ higher order skills like application, analysis and thus, help them comprehend the topic better (Hwang and Esquembre, 2003; Joyce et al., 2000). RY Field trips can provide students with meaningful contexts where they caAn connect their knowledge with the natural world and see examples and practical applications ofR scientific concepts or processes (Tytler, 2002; Griffiths and Moon, 2000). Fieldwork is not aIlwBays possible due to a limited teaching budget and increasingly busy curricula. Yet, teachers cLan bring the natural world into the classroom by providing live plants, animals, pictures, moNdels and the display of student work (Griffiths and Moon, 2000). A Recently, there has been much emphasis on parDticipatory classroom activities because there is a general agreement that effective learningB reqAuires students to be active in the learning process (Parkinson, 2004). In addition, researche rIs believe that the more students are involved in the learning process, the more they learn theF topic (Deboer, 2002). Taras (2002) suggested that student-centred learning has, in theory, pOromoted and brought about greater student participation and involvement. That for students Yto b e at the centre of the learning and teaching process, their needs and requirements must bIeT at the heart of this process, meaning can only be formed in students‟ minds by their ownS active efforts and cannot be created by someone else for the students. He explained further thatR this suggests that students are not simply passive recipients of information from the teacher, VcomEputer, textbook or any source of information during the learning process. That they have to wreIstle with an idea in their own minds until it becomes meaningful to them. Joyce et al (2000) staNted that the opportunity to exchange views and share personal experiences produces the 'cognitivUe conflict' that is fundamental to intellectual development. They suggested that in order to foster cognitive conflict, students need opportunities to pose questions about science, to work with others, to conduct investigations, present and defend their ideas, solutions, and findings, and assess their own and other students' reasoning. They wrote further that all these imply that they need to participate in the learning processes. 44 Deboer, 2002 and Stepanek, 2000 wrote that active learning techniques can empower students to make good decisions and take an active role in their own learning, increase their motivation to learn, foster and value the diverse choices of students and reduce disciplinary problems. They explained that researchers believe that this is as a result of a sense of ownership and personal involvement that active learning creates, that in active learning contexts students see their work as important because they feel important and their ideas and findings are valued. Amos (2002) argued that students‟ active participation also requires a positive, supportive learning environment in which they feel free to ask their own questions, express their ideas and thoughts and receive support and encouragement. He explained further that when students realise that theiRr idYeas and thoughts are valued and treated with respect by the group members, when they aActively involve themselves in group activities, they feel more confident, and thus, participate moRre in the activities. Many different methods and strategies have been suggested for involvingI sBtudents in lessons and engaging them in active learning (Deboer, 2002; Goodrum et al., 20 0L2; Trowbridge, Bybee and Powell 2000). However, in order for any method to be successfNul, effective lesson planning is essential. A lesson plan requires teacher to be clear about thAe sequence of the activities in the lessons, the purpose and goals of the lessons. The planninDg process involves clarification of the roles of the teacher and students. Thus, it makes Bit eAasier for students to follow the teacher‟s material and encourages them to participate more iIn the lesson and take responsibility for their own learning. For these reasons, effective lesson Fplanning has a positive effect on students‟ learning (Glenn, 2001). He explained further thaOt according to the above, teachers should allow some flexibility in lesson planning in orderY to e ncourage students to participate more in the lessons, that it is important to be sensitive to thIe Tmood of the class and if something is not going well to abandon it and move on or change taskS completely. Otherwise, a rigid lesson plan potentially hinders rather than helps the teaching-lRearning process, since it could prevent students from being involved in the lessons and reduce thEeir creativity. QuestioIniVng is the most common strategy that teachers use for involving students in the learning proNcess (Amos, 2002; Glenn, 2001). Amos (2002) reported that up to one-fifth of what a teacher sUays in a classroom is likely to be in the form of questions. Amos, (2002) and Glenn, (2001) advised the teachers to ask open-ended, higher level questions from their students so as to encourage them to find out answers to the problems at hand and reveal their own ideas and thoughts. Also that if teachers ask open-ended questions, they allow students to think freely and flexibly, to express their own ideas and thoughts without thinking that they have to give one „right‟ answer and they promote successful discussions that stimulate student participation. Amos (2002) 45 argued that closed and subject-oriented questions that rely on linear processes and logical reasoning discourage students from thinking differently from the teacher and may deter students from answering the questions asked. In addition to the nature of the questions asked, the process of asking questions is also important for students‟ learning and development. Providing sufficient „wait time‟, about 3-5 seconds, after asking a question for students not only increases student participation but also provides them with opportunity to think critically and create more ideas and responses (Amos, 2002; Trowbridge et al., 2000). Role-playing can also be a useful teaching and learning activity to encourage students to participate more in the lessons and facilitate their understanding. However, researchersR repYort that role-playing in science lessons is underrated and underused, often because of misconAceptions about what role-play is and how it can be put to use in science education (McSharryR and Jones, 2000). They pointed out that the theory behind the use of role-play in scienceI Bteaching and learning supports ‘active‟, „experiential‟ or „student-centred‟ learning. Therefore ,L students are encouraged to be physically and intellectually involved in their lessons to allow tNhem to both express themselves in a scientific context and develop an understanding of difficuAlt concepts and help them to learn complex topics. D Inquiry-based teaching and learning (DebBoerA, 2002; Trowbridge et al., 2000) and cooperative learning groups (Goodrum et al., 200 1I) are also useful contexts where students actively participate in learning process to develop thFeir own understandings of scientific knowledge. In short, student participation is necessa ryO for their learning. Active participation can increase students‟ learning, understanding andY motivation to learn. Teachers should make sure that students are mentally active in the lessonIsT and create opportunities for them to participate in the lessons. In recent years, there has beeSn a growing movement to integrate inquiry into science education (Deboer, 2002; King, SRhumow, and Lietz, 2001; Trowbridge et al., 2000). The importance of inquiry grew froVm EDewey‟s ideas. Cimer (2007) citing Dewey suggested that citizens in a democratic sociIety should be inquirers with regard to the nature of their physical and social environmenNts and be active participants in the construction of society. That they should ask questionUs and have the resources to find answers to these questions, independent of external authority. Since there is a shared, collaborative aspect to life in a democratic society, students also need to develop a capacity for communal inquiry into the nature of the world. That therefore, formal education needs to give students the skills and dispositions to formulate questions that are personally significant and meaningful to them. Trowbridge et al., (2000) defined inquiry as the process of defining and investigating problems, formulating hypotheses, designing experiments, 46 gathering data and drawing conclusions about problems. A potential result in inquiry-based teaching enables students to gain insights into the nature of scientific inquiry and understand how and why to apply the scientific method at the same time as they come to understand the subject. They can also understand what science is like and what scientists do (Amos and Boohan, 2002). Engaging in inquiry can also help students develop a wide range of skills, such as psychomotor and academic or intellectual skills Psychomotor skills involve doing something physical, like gathering and setting up apparatus, making observations and measurements, recording data and drawing graphs while academic or intellectual skills include analysing data, making comparisons, evaluating results, preparing reports and communicating results tRo thYe others or the teachers. Furthermore, students‟ attitudes and dispositions such as curiosity, Ainquisitiveness, and independence of mind, freedom from external authority, and a personal sRearch for meaning about the world can also improve. Therefore, it would appear that inqIuiBry-based learning can prepare students to be lifetime learners rather than classroom-only lear nLers (DeBoer, 2002; King et al., 2001; Trowbridge et al., 2000). N It is not enough to supply only a sterile classroom oAr lecture hall for students. Instead students need a range of resources including books, a AlaboDratory with enough equipment, library, and computers (Joyce et al., 2000; Trowbridge et alB., 2000). Teachers should provide focus, which means that inquiry is a purposeful activity, a sear chI for particular meaning in some event, object or condition that raises questions in the inquirFer‟s mind. It is stimulated by confrontation with a problem. Knowledge is generated from inOquiry. They should provide 'low pressure'. This indicates that students will gain their reinforceYments directly from the success of their own ideas in adding meaning to the environment. IIn Torder to provide 'low pressure' to students, teachers should be positive and flexible to encoSurage students further (Joyce et al., 2000). There is also need for a positive and supportive Rlearning environment in order to foster student inquiry and to encourage students to ask VtheiEr own questions. In non-threatening and trusting classroom environments, students can shIow their willingness to seek understanding and express their curiosity. On the contrary, in Nsuch classrooms where the conditions are not supportive and encouraging, students may not put Uforward questions (Alsop et al., 2002; Amos, 2002; McKeon, 2002). Joyce et al (2000) stressed the teachers‟ role in encouraging student inquiry is often dependent on the creation of a co- operative social environment, where students learn how best to negotiate and solve conflicts necessary for problem-solving. They suggested that teachers should also guide students in methods of data collection and analysis, help them frame testable hypotheses, and decide what would constitute a reasonable test of a hypothesis' (p98). 47 Effective teaching requires teachers to check continuously the development of students‟ understanding and give detailed positive feedback in order to make sure that students correctly integrate new knowledge into the existing knowledge structure (Cimer 2007). In addition, in order to identify and correct students‟ mistakes at an early stage before they become too deeply embedded, teachers need to continuously monitor and evaluate students‟ understanding (Hipkins et al., 2002). The process of evaluating students‟ work or performance and using the information obtained from these practices to modify teachers‟ and students‟ work in order to make teaching and learning more effective is known as formative assessment. Research has shown that it has great potential for improving the quality of teaching and learning and that it is the essentiaRl feYature in good teaching as well as in efficient learning. Furthermore, if assessment occuArs early in the teaching-learning sequence, it can reveal information about students, which caRn be used to guide the planning of teaching so that it takes account of students‟ existing concepItiBons (Cimer, 2007). The emphasis of formative assessment on providing students w iLth continuous feedback on their performance aims to engage students in self assessment of theNir learning, and hence, it can be argued that formative assessment can increase student participaAtion in the learning process (Cimer, 2007). Students engaging in self assessment have more cDontrol over their learning and use the feedback to modify their learning behaviours (GoodBrumA et al., 2002). Feedback helps students find out how well they understand the new material, w hIat they have done correctly and what their errors are (Joyce et al., 2000). Therefore, educatorFs reported that effective teachers frequently provide feedback specific to the subject matter be iOng covered and if necessary, take remedial action, such as providing further explanation or repeYating the key ideas and concepts. Taking such remedial action can improve students‟ learning. ITThe important point in giving feedback to students is to help them discover their own mistakesS, rather than simply telling them what they have done wrong or the pieces they are missing (RTytler, 2002; Stepanek, 2000). Many reseVarcEhers such as Akiri and Ugborugbo (2009), Oredein and Oloyede (2007), Ezeasor (2003) Iand Olatoye (2002) worked on the influence of teacher effectiveness on students‟ learning ouNtcome as measured by students‟ academic performance. For example Akiri and UgborugUbo (2009) researched on the influence of teachers‟ classroom effectiveness on students‟ academic performance, reported that effective teachers produce better performing students. Also Ezeasor (2003) in her study on school environment and teacher effectiveness, found that teacher effectiveness has a positive and significant effect on students‟ achievement in biology. Osokoya (2002) also discovered that effective science teaching depends largely on the teacher and availability of equipment. In her own contribution Erinosho (2003) wrote that the problem is that 48 science as it is taught in schools is abstract and not relevant to students‟ experience, also the approach to science learning in typical science classes is mainly by parroting and regurgitation of facts with virtually no link with the immediate environment of the learners. That this is most inappropriate as it does not promote deep understanding and application of scientific principles and theories. Olatoye (2002), in his own findings concluded that the problem of low performance of students in the science subjects is therefore a major reason why teaching and learning of science should be improved in our schools. That we cannot hope for science and technological development in a situation where performance of students in the science subject is on the downwardR treYnd. He suggested that science subjects must be taught in line with the objectives of scienceA teaching, that one of the urgent needs in Nigeria is how to improve the teaching and learning oRf science. That the condition of science teaching and learning in schools is very discouragIinBg, and it calls for all stakeholders of education to rise up to these challenges in the interest o f Lnational development. That the teaching and learning of science needs serious improvement beNcause of the low performance of the students in science subjects, chemistry inclusive. A It has been reported that the manner in which science Dsubjects are taught in Nigeria secondary schools shows that majority of science teachers use the tAraditional lecture method approach (Abudu and Gbadamosi 2014, Agbowuro, 2008; Usman ,I 2B000). Findings from studies show that most science teachers do not encourage studentsF‟ active participation in the teaching and learning process. There is also inadequate provisOion for practical activities and those provided are often inappropriate to produce the desiredY le arning effects. Experiments in science subjects are often turned into demonstrations by theT teacher for students to observe and to copy notes draw diagrams during chemistry lessons. EfSfectIive science teaching and learning ought to involve students‟ active participation in the teachRing and learning process. Lack of such active participation of students has been identified as onEe of the factors responsible for poor academic achievement in science subjects (Cleaves and ToIpVlis, 2007). AccoNrding to Greenwald (2000), the best way for a student to learn science is to experience challengUing problems and the thought and actions associated with solving them. In his own contribution Ekpete (2002), wrote that in order to solve chemistry problems in an acceptable manner, the problem solver must have both the conceptual, scientific and procedural knowledge. Mathematics problems are often encountered in areas of science and technology industries, economics, education, military warfare, medicine and even in government and these variety of problems require acceptable mathematical solutions. Problem-solving in mathematics is based on 49 some closely interwoven criteria. For example, one mathematical concept of matrices in Algebra can be used to solve a multitude of problems arising from diverse academic fields such as Physics, Chemistry, Economics, Sociology, Psychology, Geology, Astronomy and Statistics (Sule, 2000). The particulate unobservable nature of particles and mathematical nature of much of chemistry content make chemistry difficult to learn and understand (Taber, 2002). Reviewed studies show that the achievement tests scores of students are used as a measure of not only the students‟ achievement but also the teachers‟ achievement, performance and effectiveness (Hudson, 2007). Researchers such as Joshua, Joshua, and Karitsoms (2006) and Berk (2005) were of the opinion that test based students‟ achievement gains have predictiveR poYwer but provide little insight into both the teachers and the students‟ strengths and weakAnesses, except factors such as students‟ attitude, classroom environment such as class size, teacRhers‟ qualification. This is the reason why this study looked into these factors and the researcheIr Bmade sure the teachers in the researched schools are professionally qualified. Also the s cLhools have the necessary apparatus for the study. AN 2.4 Problem-Solving as an Inquiry-Based InstruActioDnal Strategy The first attempt to cite problem-solviBng as a useful teaching strategy was made by John Dewey cited by Raimi (2002) in his book “ HIow we think”. In his view, reflective thinking is the aim of education. It would innate activOity wFith a deliberate and conscious goal, which can result in planned procedure and possible iYnve ntion. The five phases of his reflective thinking heuristics expressed in instructional terms rTeveal the rudiments of the present conception of problem-solving stages. From a review of liteSratuIre on various problem-solving models, the five step model of John Dewey passes as a benchRmark because all present models are predicted on this plan with either one or two steps plus or minus the five steps model he enunciated. AlthougVh thEis study was concerned with problem-solving, the researcher realised the non- unitary natuNre oIf the term and was compelled to give a more introspective meaning of the word „problem‟. According to Oxford Advanced Learner‟s dictionary problem is “a thing that is difficult to deal Uwith or to understand, or a question that can be answered by using logical thought or mathematics” Pg 1157. „Problem‟ is seen as occurring in a situation where there is some obstacle between the given problem and the goal. If an academic problem is perceived as this barrier or intervening variable, then it requires planning, thinking and channeling of thought process towards finding solution to the problem. The ability to overcome the barrier will also depend on whether or not the problem-solver possesses sufficient information in his memory. To the researcher what is 50 considered problematic is relative, in a laboratory situation for instance, a „problem‟ arises when the student faces an experimental task to which answers or solutions are not readily available. A number of problems exist in nature for which solutions are being sought in everyday life situations (Sule, 2000). In his own contribution Rusbult (2008), defined a problem as any situation where one has an opportunity to make a difference, to make things better. Reid and Yang (2002) provided a way to categorise problems by considering the data given, the method to be used, and the goal to be reached. That there are some parallels called the „operators‟ and „operator restrictions‟. If these are all known, then the problem is simply a routine application of a known procedure to haRndleY data to reach an established goal– an algorithmic exercise. On the other hand, if none of Athe three (data, method and goal) are known then the problem is truly an open one. With these thRree variables, they specify eight types of problems (Table 2.1). IB Table 2.1 The eight problem types L Type Data Methods N Goals/outcome 1 Given Familiar A Given 2 Given UnfamAiliDar Given 3 Incomplete IFaBmiliar Given 4 Incomplete F Unfamiliar Given 5 Given O Familiar Open 6 Given Unfamiliar Open 7 IncompIlTete Y Familiar Open 8 IncSomplete Unfamiliar Open In all spheEresR of human endeavours especially in the educational sector, solution to problems or surImVounting an obstacle is the ultimate goal of man. This brings us to the concept of „problem soNlving which is the hub of this work. The Oxford Advanced Learner‟s Dictionary defines it as “thUe act of finding ways of dealing with problems”. It has become fashionable to view ability to solve problems (theoretical or practical) as an index of learning. Problem solving is also seen as the highest form of human mental activity, it is converting an actual current state (the NOW-state) into a desired future state (the GOAL-state) (Rusbult, 2008). Orimogunje (2008) described it as the ability to reason logically, think critically and at the end solve problems that come the learners‟ way in the environment. It requires overcoming all the impediments in reaching a goal (Bilgin, 2005). In 51 his own contribution Kirkley (2003) wrote that in the early 1900s problem-solving was regarded as a mechanical, systematic and frequently abstract (de-contextualized) set of skills such as those employed to solve riddles or mathematical equations. Problem-solving involves knowing what to do in the situation of not knowing what to do. It is not only finding the correct answer, but also applying appropriate actions which cover a wide range of mental abilities. Students should realize why and what they are doing, and know the strengths of these strategies, in order to understand them completely and be able to select appropriate ones (Erol, Selcum and Caliskan, 2006). In the words of Erdemir, (2009), “Problem- solving also involves a student‟s willingness to accept challenges. Accepting a challeRngeY in this context means that the student is willing to find appropriate methods to solve a probAlem”. Problem- solving means the application of already acquired knowledge of ordered scienceR process skills (by the solver) to arrive at solution to novel and related chemical problem (RaimIBi, 2002). In the context of this definition the level of the process skills possessed by the solver (Lstudent) is very important, because this is what he or she will apply when solving the probleNm. Hence the assessment of the level of the chemistry process skills possessed by the studenAt after exposing him or her to the treatments were determined in this study. Problem-solvingD is a mental process and is part of the larger problem process that includes problem finding Aand problem shaping. It is considered the most complex of all intellectual functions, pro bIleBm-solving has been defined as higher order cognitive process that requires the modulatioFn and control of more routine or fundamental skills. There are several methods of studying pOroblem-solving which are: Introspection, Behaviourism, Simulation, Experiment and ModelinYg (W etzel, 2008). This study is on Experiment and Modeling. To the researcher probleTm-solving is the application of the skills possessed by the problem solver (student) during the gSuidIed procedural step by step teaching and learning to solve problems in the environment and Rfor technological development of the nation. Some common elements of problem-solving are oEbvious from these definitions and explanations:  ExistIeVnce of a problem.  INmminence of a solution. U Potential problem solver.  Possession of relevant information and process skills needed to solve the problem.  Proper application of previous knowledge (content and procedural) process skills to the solution of the problem. Problem-solving is a higher order cognitive skill which demands many abilities, sometimes requiring much effort from the solver. It is a process in which various reasoning patterns are 52 combined, refined, extended and invented. It is much more than substituting numbers in well known and practised formula. It deals with creativity, lateral thinking and formal knowledge. Research has tried to correlate some cognitive variables, such as formal operational reasoning, working memory capacity, specific knowledge, concept relatedness and idea association, to science achievement and problem-solving ability (Lee, Tang, Goh and Chia, 2001). Problem-solving is the process of investigation where the solution is not obvious to the investigator at the initial stage. The relevant concepts in the cognitive structure of the student must be adequate before the students will be able to solve a given task or problem effectively. A number of theories of learning processes have revealed that the only way an individual can learn how to solve confronting pRractYical life problems is through the ability to solve many of such daily practical problemsA (Sule, 2000). Students who can successfully solve a problem possess good reading skills, Rhave the ability to compare and contrast various cases, can identify important aspects of a proIbBlem, can estimate and create analogies and attempt trying various strategies, problem-solving Lis a situational and context bound process that depends on the deep structures of knowledge Nand experience. The process of teaching problem-solving is a suitable approach which involveAs students in higher order thinking operations like analysis, synthesis and evaluation (NormAah aDnd Salleh, 2006). In active learning process, learning is no lonBger a standard process, but it transforms into a personalized process. Here, the skills of problem- sIolving, critical thinking and learning to learn are developed. Humans face various problems in tFheir lives and they try to find particular ways to solve these problems. In this respect, it is imp oOrtant for students to be prepared for the future by facing real or real-like problems in their learYning environment and producing appropriate solutions to these problems. What is expected fromI Teducation is to enable individuals to become an effective problem solver in their actual lives S(Chin and Chia, 2004; Walker and Lofton, 2003). In problem-based learning model, main tooRls which are used can be stated as the case study method, problem-solving based learning apVproEach, project-based learning approach and cooperative learning approach. The problem-based lIearning model which is closely connected to these learning models and methods seems to be Nenriched by increasingly spreading new methods such as „portfolio based learning‟ and „experimUental learning‟ (Akınoğlu. and Tandoğan, 2007). This study is on problem-solving based learning approach. 2.5 Problem-Solving Models Several researchers in problem-solving process have developed different theoretical models content-based domain. The previous knowledge of the problem solver was not taken into 53 consideration. Based on this flaw, researchers in content based domain argue that success in solving a problem depends on the learners‟ conceptual and procedural knowledge based on step by step approach. The following researchers developed models with different steps Wallas, Dewey, Polya, de Bono, Gordon, Newell and Simon and Meadows cited in Ishola, (2000). They based their problem-solving process on prescriptive models studies, focused on regulative acts of the problem solver in a content free domain. Consequently researchers shifted their base to systematic approach which will enhance success and confidence in tackling problems. Many problem-solving models have been used in science instruction and much research has centered on problem-solving in terms of what models/ strategies teachers and learners use in solving different types of prRobleYms and difficulties encountered in problem-solving (Ashmore, Frazer and Casey, Mettes, APilot, Rossink, Karamer-pals, Slack and Steward, Smith, West cited in Ishola, (2000), OnwioduoRkit, (1989); Ikitde, (1994); Ige, 2003). Common to all the models are four distinct stages in proIblBem-solving:  Problem definition. L  Selection of information for solution. N  Reasoning from problem to solution stDage.A  Evaluation. A In her investigation of aspects of studen tsI‟B problem-solving difficulties in ordinary level physics, Ishola (2000) identified the followiFng as major components of any numerical physics problems where students usually have d ifOficulties. These are: probable difficulties associated with understanding given questions and Ytheir values, knowledge of physical units in which derived answers are expressed, possessiIonT of relevant numerical skills. She is of the opinion that problem- solving starts with a person‟s identification and understanding of the issue in question. This skill, according to her depends Son knowledge of the content as well as the way the problem is linguistically posed. EIshRola (2000) citing Egbugara devised what he called Ibadan Seven Step Physics ProblemV-Solving Model (ISSPPSM) to be used by physics teachers and students of secondary schooIls in Nigeria to solve numerical problems in physics. Ishola (2000) adopted this model aUnd cNompared the effectiveness with the amalgamation of Selvaratnam-Frazer model with additional intensive practice, feedback and remediation strategies, which enhanced students‟ intellectual knowledge and problem-solving behaviour. Few models were developed for practical and experimental problem-solving, these are: Laboratory Problem-Solving Model (LAPSOM) by Onwioduokit (1989), Researchers Experimental Problem-Solving Model (REPSOM) by Ikitde (1994) and Inquiry- based framework for practical problem-solving by Ige (2003). 54 Inquiry-based framework for practical problem-solving adapted by Ige (2003) from West (1992). It is also a seven-step model as follows: 1 Identifying problem. 2 Identifying issues related to the problem. 3 Framing objectives. 4 Determining strategy. 5 Embarking on activities. 6 Presenting and discussing of result. 7 Evaluating of performance. RY This study made use of two problem-solving models which are: Laboratory PrAoblem-Solving Model (LAPSOM) by Onwioduokit (1989) and Hands-on and Minds-on ProblRem-Solving Model (HAMPSOM) developed by the researcher. LIB Laboratory Problem-Solving Model (LAPSOM). N This was developed by Onwioduokit (1989). The develoAper found that the existing problem- solving models in science were principally designed for aDnd applied only in theoretical contexts. His review of literature does not reveal any previoBus aAttempt to apply existing problem- solving models in practical (laboratory) contexts. He und eIrtook the construction of a Laboratory Problem- Solving Model (LAPSOM) to facilitate studenFts‟ development of skills in practical physics. It is in two parts. The first part shows a generalO strategy for solving practical problems, it specifies the systematic processes for laboratory Ypro blem-solving. The second part concerns how students are taught to use this systematic apIprToach (Instructional Guide) (p 74-75). The first part of LAPSOM consists of five procedural sStages which altogether comprises eight action steps (Figure 2.2). The reversible nature of the pRrocedure ensures cognitive and process flexibilities which are required at each stage for arriVvinEg at the problem objective. I N U 55 Y RA R LIB AN AD IB O F ITYS VE R NI U Figure 2.2 Laboratory Problem Solving Model (LAPSOM) LAPSOM Part One: General Strategy Stage 1: Recognize the problem and apparatus 56 Any meaningful attempt to solve a problem should start from a correct identification of the problem. The first step in LAPSOM requires that the students should be able to recognize the main problem given and to break it down to sub problems. He should be clear as to what experiment is required and what problem the experiment seeks to solve. He should be able to identify the apparatus provided and clearly understand their functions. Stage 2: (a) Recall Background information Practical problems are always content-referenced. Therefore the information which a student needs for arriving at a solution as well as the reasoning processes which lead to Rthe Ysolution of the problem are important factors. The first step in this stage therefore demands thAat the problem- solver does a “backward reasoning” to bring to mind the theoretical backgroundR of the problem. It is with such background that he would be able to have a clear picture of theI eBxperiment and be able to handle the variables, mathematical relationships between variables, a sL well as be able to sketch a diagram of how he intends to set up the apparatus. N A Stage 2(b): Make prediction D This sub-stage involves making tentative hyBpothAesis (predictions) about the solution of the problems. This is forward reasoning. With th isI, the relationship between the dependent and independent variables, the nature of expected Fgraph and perhaps the solution to the problem could all be predicted. Y O Stage 2(c): Drawing up a table foTr data The combination of fSorwIard and backward reasoning will enable the problem solver to draw up an appropriate table foRr data expected during experimentation in stage three. E Stage 3(a): ExpIeVriment With the infNormation obtained in stages one and two, the problem-solver is expected to design an experimUent, set up and manipulate the apparatus in order to solve the problem. This sub stage is referred to as the main laboratory session. Stage 3(b): Make more reliable predictions from data On obtaining data as an outcome of manipulating the apparatus, the problem solver at this stage matches the tentative prediction made in 2(b) with the data in order to formulate more reliable 57 hypotheses (predictions). This sub stage marks the beginning of the post laboratory session that ends in stage five. Stage 4: Analyze the data The data obtained from the experiment is subjected to some statistical treatments including graph plotting. The type of analysis made is often determined by the nature of the problem identified and the preliminary analyses made. Appropriate calculations are then carried out to arrive at solutions to the problem(s). AR Y Stage 5: Evaluate solution and experiment R The problem-solver needs to substitute the formulated or given daItaB to see whether or not there exists a balance between both sides of the equation. Also he m atLches the solution obtained with the modified predictions; he explains results and makesN suggestions for an improved experimentation to solve similar problems. DA Theoretical background of Laboratory Problem-BSolvAing Model (LAPSOM) The laboratory problem-solving model (L AIPSOM) has its root in the process approach of science and in the philosophy of instrumentaliFsm derived from John Dewey‟s Pragmatic view cited in Onwioduokit (1989). O Dewey‟s five steps of pragmatic probYlem -solving are as follows: (1) Sensing the problem. T (2) Locating it and delSimitIing it precisely. (3) Collecting possRible data that is, thinking of possible solution. (4) Sifting dVataE, that is, weighing the merits and demerits of the possible solutions and (5) SelectIing one solution for verifying and accepting or rejecting it according to the outcome ofN the experiment. UThroughout Dewey‟s career, he stressed the importance of having pupils learn scientific method or problem-solving through reflective thinking. LAPSOM was adapted from other existing problem-solving models Mette, Ashmore, Frazer and Casey and Frazer. Three things are centrally crucial in any problem-solving model, be it for theoretical, numerical or practical problem-solving. These are: (1) Identification of problem. 58 (2) A search for solution and (3) Evaluation of solution. It is mostly upon these three phases that other phases or activities are built. Hands-on and Minds-on Problem-Solving Model (HAMPSOM) The researcher developed this model that will meet the needs, demands and complexities of practical, experimental and theoretical problem-solving in science. The procedural guide (instrumental) is in two parts. The first part shows a general strategy for solving problems in science by specifying the systematic processes to such experimentRal pYroblem- solving (Figure 2.3). The second part is concerned with how students are guided byA the teacher to use this systematic approach and can also be regarded as the operational phase (Instructional Guide) (pg 76-78). IB R L HAMPSOM Part One: Structure and General Strategy N The first part of this problem-solving model consists oAf five procedural stages which are further broken down into fourteen action steps as shown inD figure 2.3. These stages are sequential, hierarchical (one concept leads to another) and the BdegAree of success achieved at a stage leads to that of subsequent stages. This in turn ensures co gInitive and process flexibilities needed during the teaching-learning process until solution is obFtained. For instance errors made in the manipulative phase of an experiment are likely to lead tOo erroneous observations, which in turn will cause wrong or incomplete conclusions to be draYwn considered from the conventional perspective of teaching science. Stage 1 is referred to as pTre laboratory session, stages 2 and 3 as the laboratory session and stages 4 and 5 as post laboraStoryI session. The details of the stages are as below: R Stage 1A: ProbleVm PEerception A correct Iidentification of a problem should be the start of any worthwhile attempt at finding solution to aNny problem. A student (problem solver) should therefore read with understanding any practicalU question posed and be able to state the problem in a clear and unambiguous terms. Without a clear concept of the problem or what the experiment specifically demands which is the aim of the experiment, he cannot identify the apparatus. Stage 1B: Acquiring Related Theory 59 The theoretical aspect or the content is the foundation of practical problems. The information which the students need for arriving at the solution and the reasoning processes which lead to the solution of the problem are important factors. This background would enable them to have a clear picture of the experiment and be able to tackle the remaining stages. Stage 1C: Planning Experiment The knowledge of the content enables the students to draw the diagram for the experiment, identify the apparatus and arrange them according to the diagram. RY Stage 2A: Recalling Theory and Making Tables. A Any student that is lacking in the theory of a particular experimentR is bound to have problems with the interpretations, discussions and conclusion of experimenItB. Being fully equipped with the theoretical background, the student would have a clear pic tuLre of the experiment and experimental process and can predict tentatively what the result iNs likely to be if the experiment proceeds favourably. Appropriate tables can now be drawn, knoAwing the nature of results expected. Stage 2B: Experiment: D This is the stage that lends itself to discover tBhe aAnswer or solution which cannot be determined by merely looking it up in a science te xItbook. This act of mental manipulative exercises can lead to acquisition of skills and evaluatingF an original design. The experiment should be repeated and more than one readings take nO. Stage 3A: Observation Y The student is always SexpIe Tcted to make accurate report of any observations made without recourse to theory. To foRrestall falsification of results, the teacher should always insist on seeing the result of any observaEtion made before being recorded by the problem solver (student). By so doing the students willI lVearn the art of trained and accurate use of senses to collect information. Stage 3B: CNollecting and Recording Data DUata collection and recording are very important any error at this stage will affect the result and may lead to performing the experiment again. These involve the different methods of data collection, drawing tables for recording of such data. Stage 4A: Analysing of Result 60 Data collecting and data analyzing form a continuous process in that, the data collected determines the direction of the analysis. The use of appropriate method of analysis is important. Stage 4B: Interpreting, Predicting data and drawing conclusion. This section requires the student to explain the results collected by several observations as well as attempt a synthesis of the data accumulated during the investigation. Such explanation is based on existing knowledge in the area. If the student fails to obtain correct results, he has experienced the experimental process and possess the necessary skills. He is in the best position to highlight sources of error and to suggest improvement to the design of the experiment. FRor thYe students will find it easier to reject his incorrect hypothesis which he proposed asA a result of his experimentation. BR N LI A FURTHER EXPLANATIODN 5B. A CONSOLIDATING 1A. IB KNOWLEDGE GAINED PR OBLEM PERCEPTION CHANG EO DE FSIGN 5A ITY EVALUATION OF S RESULT AND METHODS. CHANGE TECHNIQUE 1B. ER 4B. AC QUIRING RELIAVTED INTERPRETING, TH EORY N PREDICTING DATA AND U DRAWING CONCLUSION 2A. RECALLING 4A. 1C. THEORY ANALYSING RESULT PL ANNING EXPERIMENTS 2B PERFORMING EXPERIMENT OR PRACTICAL6 1 3B COLLECTING AND RECORDING DATA Figure 2.3: Hands–On and Minds-On Problem-Solving Model (HAMPSOM) Y AR Stage 5A: Evaluation of Result and Methods R The student having completed his investigation is asked to look IbBack at his results and methods and suggest new ideas and ways to conduct the investigation. L N A Stage 5B: Consolidating Knowledge Gains and Change in TDechnique. If the result is considered sound following a proAper procedural appraisal, a solution is said to be at hand. Sometimes more in depth exam IinBation of the sources of error could lead to suggestions on the improvement of the design Fto yield better results or by giving further explanation by the teacher. A change of technique ma yO be necessary if the result is not the expected one. For this study the effects of LaboraYtory Problem-Solving Model (LAPSOM) and Hands-on and Minds-on Problem-Solving ModTel (HAMPSOM) and control using their instructional guides on students‟ attitude to and acShievIement in practical chemistry were determined, and compared to know which effect is greRater. E Theoretical bacIkVground of Hands-on and Minds-on Problem-Solving Model (HAMPSOM) The fivNe phases of John Dewey cited by Raimi (2002) reflective thinking heuristics expressed in instruUctional terms reveal the rudiments of the present conception of problem-solving stages. From a review of literature on various problem-solving models, the five step model of John Dewey passes as a benchmark because all present models are predicted on this plan with either one or two steps plus or minus the five steps model he enunciated. HAMPSOM was developed using the knowledge of two problem-solving models by Selvaratnam and Frazer (1982) and Ikitde (1994), 62 because of the unique nature in using the philosophy and instrumentalism of John Dawey‟s pragmatic view with the four distinct stages in problem-solving models: These are:  Problem definition.  Selection of information for solution.  Reasoning from problem to solution stage.  Evaluation. In addition HAMPSOM incorporated intensive theoretical background and teacher Yguided discovery learning. Selvaratnam and Frazer (1982) develop more attractive model for chemistry. R The model specifies five steps: A (i) Clarifying and defining the problem BR (ii) Selecting the key equation LI (iii) Deriving the equation for the calculation (iv) Collecting the data, checking the units and calculatiNng (v) Reviewing checking and learning from the soDlutiAon. Researchers Experimental Problem-Solving Model (AREPSOM) This is a five step model developed by Ikitde (1I9B94) for biology. It is a straight chain model connected to sub groups irreversibly. These are: 1A Problem perception F 1B Selecting apparatus O 2A Recalling theory Y 2B Making tables IT 3A ExperimenRtatiSon 3B ObservEation 3C RIecVording data 4A N Analysis of Results 5UA Evaluation of solution 5B Consolidation knowledge gains 5C Change in technique. 2.6 Students’ Attitude to Science and Practical Chemistry According to Oxford Advanced Learner‟s Dictionary, attitude is the way that we think and feel about something or the way that we behave towards something that shows how we think or 63 feel. Attitude according to the Encyclopedia of Education is a predisposition to respond in a certain way to a person, an object, an event, a situation or an idea. An attitude towards something consists of a person‟s collection of facts about the subject, which may enable her to feel antipathy towards it, and manifest in either acceptance or avoidance of the subject. Oguntade (2000) defines attitude as the effective disposition of a person or group of persons to display an action towards an object based on the belief that such a person or groups of persons has about the object. Attitude towards science denotes interest or feeling towards studying science. While attitude in science means scientific approach assumed by an individual for solving problems, assessing ideas and making decision. Scientific attitudes embrace all scientific processes of gathering informatiRon wYith no subjectivity, skepticism or prejudice for the advancement of science. These proAcesses can be objectively and confidently carried out by skillful individuals (Bassey, 2002). RAmong the factors that relate to the students‟ attitude towards science, the researchers have iIdBentified the following: gender, age, education level (elementary school, secondary school, Lhigh-school, etc.), type of school (government or private school), the students‟ school results Nin sciences and their classmates‟ influence, self-image, social self perception, their family‟As socio-economic status (parents‟ education, jobs and monthly income), teaching methodsA, thDe parents‟ attitude towards sciences, the students‟ cognitive style, their interest in a certainB type of career, social view on science and scientists (Adesoji, 2008). I Learning to solve problems is a primFary objective in learning science, as problems are an inevitable fact of life. By solving probleOms, a student needs to think and make decisions using appropriate strategies. Students‟ sucYcess in achieving their goals will encourage them to develop positive attitude towards problemT-solving (Erdemir, 2009). Anderson and Dill (2000) indicated that attitudes are seen to beS dyInamic in nature and under constant change as they interact with behaviour and must be Rviewed in probabilistic rather than deterministic terms because of the complexity of structuEre of an attitudinal network. They stressed that attitude cannot be observed directly, rather IthVey have in the past been inferred from what a person says or does, that attitude measuremenNt has become a common part of research into schools and schooling throughout the world. TUhat attitude is assumed to have an affective component of how students are seen by peers and themselves. They offered some generalizations about attitude:  Students tend to have positive attitude towards school and the subject matter taught at school at all grade level.  The attitude of students towards school and school subjects tend to become less favourable over their years at school. 64  Students tend to like certain subjects e.g. science, sports, reading more than others (e.g. mathematics, writing and agricultural science). Also that the relationship between attitude and achievement is generally moderate and positive provided the sample is not contaminated by selection bias. Lastly, that attitude tends to be influenced by appropriate change in school programme. They recommended that the measurement of attitude should become more common in schools particularly since they influence future participation in schooling and subject choice. Aiken (2000) wrote that attitude affects people in everything they do and in fact reflects what they are, hence a determining factor of students‟ behaviour. RY According to Gonen and Basaran (2008), Ogunkola (2002) and Yoloye (199A4) the attitude of a learner towards science would determine the measure of the learnersR‟ attractiveness or repulsiveness to science. This will invariably influence the learners‟ choicIe Band even achievement in that subject. Normah and Salleh (2006) indicated that students‟ attitu dLe and interests could play a substantial role among pupils studying science. Several studies, sucNh as Gonen and Basaran (2008), Ajzen and Fishbein (2000) and Wilson, Ackerman and MalAave (2000) reported that students‟ positive attitude towards science probably correlate hAighDly with their achievement in science. Research has demonstrated that attitude toward science change with exposure to science but that the direction of change may be related to the qualit y IoBf that exposure, the learning environment and teaching method (Cracker, 2006). There is tFhe need to advance a variety of teaching methods, having to do with heuristic problem-solv inOg in order to promote positive attitude of student towards problem-solving (Sule, 2000). AdesoYji (2008) maintained that problem-solving strategy is probably a basic means of changing studIenTts‟ attitude towards science. The effect of solving problem on a student‟s attitude toward scieSnce is incredibly important because problem-solving requires patience, persistence, perseveranceR and willingness to accept risks (Udousoro, 2002). “In developedE countries, it has been determined that goals of science are never fully realized, that students doI nVot like science lectures and that most have no preference for science”. Though scientific coNncepts are functioning in daily life but these are difficult and complex in nature. In learningU these concepts, students‟ attitude and interests could play a substantial role among pupils studying science (Normah and Salleh, 2006). Students can succeed in science subject if they have positive attitude towards science. In science education, “The affective outcomes of instruction are as important as the cognitive outcomes. The affective domain is characterized by a variety of constructs, such as attitudes, preferences, and interests. But negative attitude toward a given subject leads to lack of interest and avoidance of the subject”. It means, a positive attitude toward science 65 will lead to a positive commitment to science that will effect students‟ lifelong interest and learning in science (Erdemir, 2009). According to Salta and Tzougraki, (2004), “Attitude is a tendency to think, feel, and act positively or negatively toward objects in our environment”. Attitude organises thoughts, emotions and behaviours towards a psychological object. Some attitudes are based on people‟s own experiences, knowledge and skills, and some are gained from other sources (Erdemir, 2009). It can be concluded in words of Craker (2006) that attitudes are learned, not inherited, that the attitudes toward science change with exposure to science, but that the direction of change may be related to the quality of that exposure, the learning environment, and teaching method. IYt can be said that a negative attitude towards a certain subject makes learning or future-learning dRifficult. “A positive attitude toward science leads to a positive commitment to science that influAences students‟ lifelong interest and learning in science” (Craker, 2006). R Erdemir, (2009) indicated that “Many researchers argued that teachiIngB methods have a great impact on students‟ attitude to learn a subject”. That‟s why the rese arLcher opted to find out the effects of problem-solving approaches on students‟ attitude Nto practical chemistry. Many researchers believe that if students are allowed to demonstratAe higher cognitive abilities through problem-solving, either through a teacher centered appAroaDch or student centered approach, their attitude toward physics might be positively affected B(Erdemir, 2009). Udousoro (2000) and Popoola (2002) wrote that students tend to show more po siItive attitudes after been exposed to self learning strategy such as computer and text assisted pFrogrammed instruction, self learning device and self instructed problem based. Hunt, Haidet, COoverdale, and Richards (2003), noted favourable student attitude towards active learning mYethods. Adesoji (2008), Akınoğlu and Tandoğan (2007), concluded that students in the IeTxperimental group may develop more positive attitude towards science subjects after the treSatment of problem-solving teaching. Similar results were obtained by Udousoro (2000) after Rusing computer and text assisted programmed instruction and Popoola (2002) after expoVsinEg students to a self learning device. Interests are considered to be the most important motivIational factors in learning and development. Abulude (2009), also reported that students‟ attNitude towards chemistry have significant direct effect on students‟ achievement in the subject. U The students‟ attitude towards studying natural sciences have been the object of some studies and research began at an individual level, by independent researchers, by project teams, or by organizations. The studies and researches carried out have shown the fact that students acknowledge the importance of natural sciences for life and career but have also pointed out a significant drop in their interest in the study of these subjects (Osborne, Driver and Simon, 2003). 66 Festus and Ekpete (2012) reported that students‟ performance in chemistry showed that the students still possess low attitudes towards problem-solving. Machina and Gokhley (2009) were of the view that “maintaining the levels of positive attitude towards science in early years is easier than transforming the negative attitude to positive attitude in the following years”. As a result of these conflicting reports on students‟ problem-solving attitude and achievement, therefore the study investigated the variables and found how it can be improved positively. 2.7 Achievement in Science and Practical Chemistry Science and Technology are interwoven and at the same time independent. TRhe YOxford Advanced Learner‟s Dictionary defines science as the knowledge about the structureA and behaviour of the natural and physical world, based on facts that you can prove for exampleR by experiments pg 1307. It defines Technology as scientific knowledge used in practical waIyBs in industry pg 1520. These definitions show that science provides knowledge while techn oLlogy provides the way of using this knowledge. This shows that science is the foundation of tNechnology. According to research the major goal of science eduAcation is the production of citizens who are scientifically and technologically literate with Aa hiDgh competence for rational thought and action. This requires that pupils understand the chBallenge posed by scientific and technological activities and the value of using a scientific a pIproach to solve their problems as well as to understand their world and universe. EmphasiFs is on methods of science teaching which have to do with students‟ problem-solving skills in oOrder to meet the present scientific and technological trend (Bilgin, 2005). There is evidence to Yshow that students generally have problem-solving difficulties and misconceptions in chemistrIyT (Adesoji, 2008; WAEC, 2007, 2005). This explains why there have been many researchers Sprobing into students‟ problem-solving difficulties and misconceptions in various aspects of scieRnce. The importanEce of science cannot be over emphasized, with its presence in agriculture, certain remote pIoVssibilities have become realities or at least very probable by the application of bio- technology aNnd genetic engineering; food production has now increased by an enormous factor and man is pUotentially capable of banishing hunger from the surface of the earth population explosion notwithstanding. The development in computer technology has brought about what is called “Second degree” industrial revolution. Man now has in power the wherewithal to solve easily most of the problems of his material existence by the application of advanced science and technology (Ananza, 2013). Science is knowledge based and process based correspondingly, science education entails the intellectual activities that are concerned with teaching of science to lead students to 67 know, understand and practice the scientific methods in their daily interactions with nature and natural phenomena. Science is basically about becoming aware, exploring, understanding and exercising some degree of control over the environment through the senses, and personal exploration. It is in part a body of knowledge about nature and in part the method or methods of generating knowledge about nature (Dogru, 2008 and Erinosho, 2003). In a world based on science and technology, it is science education that determines the level of prosperity, welfare and security of the people. The universal acceptance of the above position is responsible for the pride of place that is accorded science education in the school curricula of various nations of the world. In Nigeria, the Federal and State governments seem to haRve Yrealized that real development of their human and material resources is synonymous with thAe development of science and technology as stated in the National Policy on Education (FRN, 2R004). The adoption of the 6-3-3-4 system of education, the establishment of several State anIdB Federal Polytechnics, Universities of Agriculture, Universities of Science and Technolog y,L Ministry of Science and Technology, and the adoption of a 60:40 ratio of students‟ admiNssion into higher institutions to pursue courses in “Science” and “Arts” respectively, all tend tAo show that the nation has realized the importance of science to a modern state (Olatoye, 2002)D. Achievement is one of the most important BindiAcators in which policy makers in education are interested. The Oxford Advanced Learner‟s d icItionary defines achievement as the act of a thing done successfully especially with effort andF skill pg 11. The researcher is of the opinion that achievement is the end product of a lear nOing experience. Achievement tests are given after formal instruction to find out how much aY person has learnt so as to predict how well he will learn additional material of similar nIatTure or to indicate whether the person has the necessary skills or knowledge for future succeSss in a course of study or trade. In spite of this realization and the concomitant effort at its Roperationalization, it is known that interest, enrolment and achievement in science subjects, VhavEe continued to decline in the country (Ogunleye, 2008; Olatoye and Afuwape, 2003). I ChemNistry is a very important subject in the field of science. Its unique position and importanUce may be better appreciated when it is realized that it is necessary for the understanding and advancement of other sciences and technologies. Probably, no other science subject has such a wide applicability. Considerable knowledge of chemistry is required in areas such as Agriculture, Soil science, Geology, Biology, Agronomy, Biochemistry, Forestry, Medicine, Dentistry, Veterinary medicine, Metallurgy, Mineralogy, Pharmacy, Food technology, Textiles and Clothing Materials science, Chemical engineering, Industrial electrical/electronic e.t.c. In the context of 68 Science education, Chemistry has been identified as a very important subject whose importance in the scientific and technological development of any nation has been widely reported (Adesoji and Olatunbosun, 2008). It is one of the three subjects classified as the natural science (chemistry, physics and biology) for the Senior Secondary School (SSS) curriculum in Nigeria (FME, 2007). The curriculum is aimed at satisfying the chemistry requirements of the SSS programme in the National Policy on Education (FRN, 2004) has the following objectives;  To facilitate transition in the use of scientific concepts and techniques acquired in basic science and technology with chemistry. Y To provide the students with basic knowledge in chemical concepts andR principles through efficient selection of content and sequencing. A  To show chemistry in its interrelationship with other subjects. R  To show chemistry in its link with industry, everyday life, benefiItsB and hazards and  Provide a course which is complete for pupils not proceedi ngL to higher education while it is at the same time a reasonably adequate foundatioNn for post secondary chemistry course. A The topics are arranged into instructional units whAichD are sequenced in spiral form with each unit treated in greater detail as the course progresses. Each unit is organized under the following headings: teaching topics, performance object ivIeBs, content, activities (teacher and students), teaching and learning materials and evaluaFtion guide. The curriculum content resting on the practical and activity of the students is Orecommended to ensure that learners are provided with continuous experience in and skill ofY defining problems, recognizing assumptions, critical thinking, hypothesizing, observing, collIeTcting and recording data, testing and evaluating evidence, manipulating variables, geneSralizing and applying generalizations. In line with the current trends in chemical education cEhemRistry teaching should focus on the following broad aims:  To stVress principles and unifying concepts of chemistry without demanding mNemIorization by pupils of a vast amount of factual information and U To develop skills in investigating problems based on an understanding of practical work. (WAEC Syllabus, 2013- 2015). Problem-solving is a major characteristic of basic sciences and its neglect could hinder students‟ learning outcome in science, chemistry inclusive. As one of the basic sciences, chemistry is characterized by problem-solving. The fact that the subject is in part mathematical in nature has made the subject more problem based (Mahalingam et al., 2008; Inyang and Ekpeyong, 2000). According to Babatunde (2001), teachers hardly engage pupils in problem- solving activities which 69 is capable of promoting their ability to think. He concluded that the achievement of secondary school students in solving word problems in mathematics and physical sciences could be enhanced through such activities. Sule (2000) showed that mere is a significant relationship between the students‟ scores in attitude test and the teacher made diagnostic test. The importance and role of attitude towards science can be recognized from the researches‟ findings showing positive relationship of attitude towards science and achievement, and students with more positive attitude towards science has sustainable learning, and also want to continue with those subjects they enjoy (Craker, 2006). Detection of students‟ attitudes can have a contribution to make interests and curiosity lively and increase the success of students. Studies have reRveaYled that teaching methods influence on students‟ attitudes towards science and predicAt achievement. However, a positive attitude toward science can be developed through hands-on Ractivities and other methods of instruction that excite students and encourage them to learInB like problem solving teaching strategies (Erdemir, 2009; Adesoji, 2008; Gok and Sılay, 2 00L8). Gok and Sılay (2010) were of the view that “One of the fundamental achievements of eNducation is to enable students to use their knowledge in problem-solving” A A number of other studies on the relationship bDetween students‟ attitude and learning outcome in science show that science educators haveA not reached a consensus opinion on the relationship between the two variables. One s chIoBol of thought indicates a direct relationship between attitude and performance in science (FOlatoye, 2002), while Adesoji and Fasuyi (2001) did not establish such relationship. Festus andO Ekpete (2012) wrote that in spite of the realization of the recognition given to chemistry amoYng the science subjects it is evident that students still show negative attitude towards the subjTect thereby leading to poor performance and low enrolment. In his own contribution Akubuiro S(20I04), found that students‟ attitude towards science subjects maybe positively related to theirR performance in these subjects. He also discovered that attitude contributed substantially morVe thEan other variables in predicting achievement. Gok and Sılay (2008) worked on the effects of diIrective and non-directive problem-solving on attitudes and achievement of students in a develoNpmental science course; the result is that attitude becomes more positive after instructiUon. Sule (2000) wrote that reports of studies carried out in America on problem-solving attitude and achievement in mathematics revealed that certain elements of behaviour were manifested by learners in the process of solving mathematical problems. He went further that the ability of individuals to solve problems is to a large extent dependent on the attitude that the individual learner develops towards problem-solving. He also reported that in the Nigerian context the result 70 of a research work conducted on problem-solving attitudes and students‟ corresponding achievement in mathematics shows little evidence of correlation between students‟ attitudes and their ability to solve word problems in mathematics. While he found that there is a significant relationship between problem-solving attitudes of senior secondary school students and their level of academic achievement in the teacher made test in mathematics. Due to these controversial results the study looked into the influence of the problem-solving approaches on achievement in practical chemistry. 2.8 Chemistry Process Skills and Students’ Attitude to Practical Chemistry RY The science process skills referred to as chemistry process skills in thisA study are the foundation of problem-solving in science. These skills are separated into two Rcategories namely basic and integrated. The basic science process skills are: Observing, CIBlassifying, Measuring, Communicating, Inferring and Predicting. The integrated scien ceL process skills include: Experimenting and Interpreting data. There is a hierarchical relaNtionship between the two broad skills the acquisition of basic skills is a pre-requisite for the acqAuisition of integrated skills (Wetzel, 2008). D Basic skills A  Observing- Using the five senses to f inIdB out information about objects: an object‟s characteristics, properties, similaritiesF and other identification features.  Classifying-The process of group inOg and ordering objects.  Measuring- Comparing unknYown quantities with known quantities such as: standard and non standard unit of meIaTsure.  Communicating- UsSing multimedia, written, graphs, images, or other means to share findings. R  Inferring- VformEing ideas to explain observations.  PredNictinIg- Developing an assumption of the expected outcome. IntegrateUd skills  Experimenting- Carrying out an investigation.  Interpreting data- Analyzing the results of an investigation. This study concentrated on most of the basic skills such as Observing, Measuring, Inferring and Predicting and on the integrated skills- Experimenting and Interpreting data. Problem-solving in chemistry is a scientific process of providing an answer to a solution of a given problem situation in chemistry. Ishola (2000), wrote that problem-solving in chemistry is an 71 obstacle or barrier in the path from problem to solution. The barrier is lack of problem-solving skill which could help in solving the problem, for example a problem which requires students to determine the concentration of a particular solution in quantitative or volumetric analysis, requires the students to determine the mole ratio which is the number of moles acid, that is combining with the number of moles of base, the molar mass of the unknown solution and the expression which relates concentration to molar mass. Therefore problem-solving is a way of removing the barrier in the path of problem to solution. Discussions on problem-solving behaviour of students in chemistry seem to support the view that the difficulty which the students encounter in problem-solving is not merely due to lack of chemical knowledge, it is often with processes involved in the apRplicYation of knowledge (Raimi and Fabiyi, 2008). A Several factors influence the abilities in solving problems, from the natureR of the problem, to the learner‟s developmental level and their knowledge base, to motivatioInB and problem-solving skills (Reid and Yang, 2002). Normah and Salleh (2006) discove rLed that students who can successfully solve a problem possess good reading skills, have theN ability to compare and contrast various cases, can identify important aspects of a problem, caAn estimate and create analogies and attempt trying various strategies. “Problem-solving AinvDolves a higher level of information processing than the other functions and mobilizes peBrception, attention and memory in a concerted effort to reach a higher goal”. Due to the import anIce of problem-solving skills (chemistry process skills) which are needed in order to meet Fthe present scientific and technological trend, the possession of these skills and the relati onOship with students‟ attitude to practical chemistry were examined. TY SI 2.9 Chemistry ProcEessR skills and achievement in Practical Chemistry ScienceI Vdeals with an exploration into the known and unknown world to gather information,N acquire knowledge, skills and attitudes necessary for individuals to live effectively in the sociUety. For students to function as scientists, they must be trained in the basic skills and processes of science, including observing, measuring, classifying, identifying problems, collecting, analyzing and interpreting data, formulating hypothesis, experimentation, etc (Dogru, 2008). An examination of some science curricula currently in use in schools, show an emphasis on students involvement in science through practical activity in the classroom. This can be seen in the Nigerian Secondary School Science Projects (NSSP) in the different science subjects at the Senior Secondary School level. These offer a wide range of practical activities aimed at involving students in the 72 processes of science, so that the theoretical concepts to which they are exposed are given meaning when students see their application in real life situations (Ige, 2003). Erinosho (2003) described laboratory work as often being dull and teacher directed and so students often fail to relate the laboratory work to other aspects of their learning. She went further that practical or laboratory work could be made more interesting and effective if students are involved in problem-solving, especially if problems have relevance to their daily lives. Many surveys indicated that most of students are not able enough in acquiring knowledge independently and in the application of this knowledge to solve everyday life problems. Practical work is motivational that may be linked to the promotion of interest and social skillsR, inYvolving students in the application of substantive knowledge and also in the development oAf experimental skills. This implies that students must be helped to have a sound knowledgeR base in the major disciplines of science, in the collection, validation, representation and interpIrBetation of evidence, as well as in the development of scientific attitude. More importantly thLey need to be exposed to activities that will enable them effectively harness their experienNces for use in solving problems confronting them on a daily basis (Adesoji, 2008). Ige, (2003A) observed that in many secondary schools in Nigeria teachers give separate lessons for theAoryD and for practical. Students do not have enough opportunities to effectively apply their thBeoretical knowledge of science concepts in practical situations. Nwagbo and Chukelu, (2012 );I Akale and Usman (1993) noted that there is the tendency of teachers to muddle up practical Fwork with theory to the extent that practical work distorts students theoretical understandin gO of science content. They suggested that teachers should strive to help students integrate theoYry with the experience they gain in practical work to enable them achieve a better understanIdTing of science. That the role played by the science teachers in practical work is crucial to thSe experience that students receive. Whether he assumes the position of a dispenser of knowledgeR while students observe and memorize facts or if he is a „guide to learning‟ so student can leaVrn bEy doing. The mental processes and skills associated with science can only be acquired and deIveloped when students actually participate in science instruction through practical experience. NUsman (2000) showed that lack of adequate materials for practical activities is one of the reasUons claimed by teachers for the constant use of traditional lecture method in teaching science. The use of problem-solving approach proffers advantages for science classes as it specifies in unmistakable terms what the students are expected to do at each stage. It also helps students apply their theoretical knowledge of science concepts and skills to practical problems (Ige 2003). Senocak, Taskesenligil, and Sozbilir, (2007) found that there is probably a statistically significant difference between the problem based learning and conventional groups in terms of their attitude 73 towards chemistry, skill development and conceptual understanding. InceAka and Aydogdu (2010) also discovered that problem-solving skills probably had significant effect on achievement. Akubuilo (2004) stated that problem-solving instructional strategies, which may result in improved cognitive development, acquisition of skills and retention of subject learnt could lead to improved attitude towards solving life problems. Numerous teaching methods can be used for problem-solving strategies. Therefore the investigation of students‟ attitude, behaviours, problem-solving knowledge and skills becomes important while solving a problem (Erdemir, 2009). Lack of problem-solving skills by the students was described by Reid and Yang (2002) as non-use of the different stages of problem-soRlvinYg. That the teaching of problem-solving skills should be an integral part of science educatioAn. Also that to an extent, every problem requires the individual to possess information anRd to process this information in order to progress from a state of having a problem to the stIatBe of having a solution. Students do not have an organized problem-solving strategy and the reLfore find problem-solving difficult generally. According to Ige (2001) and Adesoji (2008)N, clearer understanding of what constitute problem-solving skills would enhance the design ofA specific instructional activities and materials necessary for the development of these skills.A ThDey found that students had difficulty in defining problem in relation to relevant data for soBlving problems. They explained further that, a number of these students who had difficulties at thIe first two stages, lack organizational skills and that affected their overall performance. ThFey stressed the need to train students to develop appropriate skills for solving problems usiOng the appropriate problem-solving model. Many tasks performed in profYess ional and daily life require problem-solving abilities. These tasks could range from designinIgT a product, solving management problem, analyzing a scientific problem like discharge of poSisonous gases or predicting flooding in an ecological zone to opening a door with a jammed locRk. Therefore incorporating problem-solving in science learning may be regarded as a stepV inE the right direction as it would equip students with relevant knowledge, skills and experience.I Suggestions from research are that instructional methods should take into account the general sNtrategies and methods of problem- solving, thus providing a tool to increase reasoning skills inU the problem solver. Life is, in essence a continuous process of problem-solving and selection from available and/or created options. Nevertheless, problem-solving abilities or decision making capacities are valuable and precious skills not only in academia, but also in the world of business and industry and in daily living. Furthermore, in science these skills play an important role in the acquisition and organization of knowledge in a meaningful way (Cardellini, 2006). Due to the importance of chemistry process skills which are needed in order to meet the present scientific and 74 technological trend, the possession of these skills and the relationship with achievement were examined. 2.10 Class Size and Problem-Solving Attitude in Practical Chemistry Class size may be broadly defined as the relative amount of instructional service in terms of professional personnel, that is brought about to bear upon the educational task (Ogundipe, 2004). He classified it into three as follows: (a) A “small” class containing 5 to 30 students. (b) A “medium” class containing 31 to 90 students RY (c) A “large” class containing 90 plus students. A For this study class size is classified into two: R (a) A “small” class size containing 40 students and below, IB (b) A “large” class size containing 41 students and above Laccording to the National Policy on Education (FRN, 2004). N Obviously, there are questions about the generalizability Aof individual case descriptions. The characteristics of the children in the school, the compoAsitiDon of the class and the qualities of the teacher and the school are all important. The fore Bgoing shows the obvious potential in smaller classes for more teaching support and focused te aIching. Professional judgment of teachers is that smaller classes allow more effective and fleFxible teaching and the potential for more effective learning. However, there is vigorous dOebate over the educational consequences of class size differences. In the United States, thYe d ebate centered on the efficacy and cost effectiveness of initiative to reduce class size. AI Tworry in the United Kingdom has been that classes are too large and that teaching, learning aSnd children‟s educational progress can suffer (Rivikin, Hanushek and Kain, 2000). R Blatchford,V MEoriaty and Martin (2003) gave account of a survey of teachers‟ and head teachers‟ viewsI showed that practitioners believed that large class size affected teaching and learning andN are particularly aware that larger classes could have an adverse effect on amount of teachersU‟ attention. They found that smaller classes resulted in greater teacher knowledge of pupils, frequency of one to one contacts between teachers and pupils, variety of activities, adaptation of teaching to individual pupils and opportunities to talk to parents, other studies reported more individual teaching attention and more feedback. They discovered that monitoring, checking understanding and offering appropriate feedback to individual children is more difficult in a large class, also learning of basic skills suffer in large classes. That teachers of large classes are under 75 stress and worn out spending many hours outside their contact time marking, the teacher child interactions are also concerned with management activities, and quelling rising noise levels. They went further that the behaviour of the pupils could be strained this is probably related to the limited amount of space that the pupils had to move in. Also grouping pupils by ability are inevitably large and included a wide range of ability. However, in direct contrast to teachers‟ views, Blatchford et al (2003) reported no statistically significant differences between class sizes for most teachers‟ activities. Class size has become a phenomenon often mentioned in the educational literature as an influence on pupils‟ feelings and achievement, on administration quality and school buRdgeYts. It is almost an administrative decision over which teachers have little or no control (AriAas and Walker, 2004 and Adeyela, 2000). Ogundipe (2004) showed that reduced class size wRith a 1:15 teacher- student ratio shows positive results on reading and mathematics. That teacIhBing may affect pupils‟ achievements and learning in a causal way. Also class size can be seen Las one contextual influence on classroom life, which plays a part in the nature of interactionNs between teachers and pupils. Again there is immense practical and financial difficulty in Asetting up large-scale experimental studies of large class size. Blatchford, Bnines, KutniAck aDnd Martin (2001) also wrote that the advantages of large class size include decreased Binstructor costs, availability of resources and standardization of learning experience. That th eI judgment and experience of many practicing teachers is that, other things being equal, teachFing and learning are likely to be improved in smaller classes. But the evidence from research i s Onot clear-cut, and some of it even suggested that although teachers may feel their teaching hasY benefited in small classes, their feeling is not supported by observational data. On logical IaTnd common sense grounds, it seems likely that the greater the number of children in a claSss, the more times the teachers will spend on procedural matters and conversely, the less timeR the teachers will spend on instruction (Hanushek, 2003). KokkelenbeVrg,E Dillon and Sean (2005) showed that class size is the primary environmental variable teacherIs must contend with when developing effective teaching strategies. They argued that while clNass size may not be significant in courses best suited for lecture style learning, courses geared tUoward promoting critical thinking and advanced problem-solving are probably best taught in a smaller classroom environment. In a review summary Fleming, Toutant and Raptis (2002), wrote that an increase in class size does not necessarily lead to a decrease in level of academic achievement. Likewise, a decrease in class size does not guarantee an improvement in the social environment of learning, more important is what the teacher does with the opportunities provided by the size of the class, that large classes versus small classes have little or no effect on students‟ 76 performance. Due to all these different findings, opinions and observations, there is the need to further research into the effect of class size on problem-solving attitude of the students in practical chemistry. 2.11 Class Size and Achievement in Practical Chemistry Class size refers to an educational tool that can be used to describe the average number of students per class in a school (Adeyemi, 2008). Some researchers such as Babatunde and Olanrewaju (2014) and Deutsch (2003) emphasized that class size is an important factor in the teaching and learning process and that it has effect on students‟ achievement. That the iRnfluYence of class size on academic performance has been the focus of both academic and Apolicy debate. Numerous studies show that there has been a sharp decline in the academic perfoRrmance of various levels of our educational system in Nigeria, and the decline has been attribIuBted largely to the poor condition in educational institutions in the country. Worse still there hLas been an upsurge in the number of both community and privately owned secondary schoolsN, accompanied with a gross lack of modern instructional technologies, poor physical classroomA conditions and lack of adequate training programme for teachers. The issue of quality Ain Dscience education goes beyond subject matter content but include classroom learning environment and school factors which have been speculated to influence achievement in science (c hIeBmistry inclusive) (Obayan, 2003; Olatunbosun, 2006). F Parents and educators universa llOy identified small classes as a desirable attribute of successful school systems and clasYs size reduction initiatives have been implemented widely. Despite this and decades of studIyT, researchers remain divided on whether smaller classes actually have positive effects on studSents‟ outcome and/or whether the magnitude of the effect justifies the high cost of implementRing class size reductions. In fact, a larger debate focuses on whether increasing resourVces Eto schools in any way improves students‟ outcome. These discussions are being carried ouIt throughout the world, with some different frame works between developed and developing Ncountries. In developed countries where access to primary and secondary education is essentialUly universal but the quality is varied, researchers are concerned with identifying specific treatments to improve students‟ outcomes, such as reduced class size, increasing teachers‟ salaries, or expanding teacher education. Developing countries are often still dealing with the tradeoff between increasing access to education and improving the quality of existing education. Improving quality in this context can mean providing textbooks and adequate facilities, more fundamental needs than are the focus in the developed world (Averest and Mclennan, 2011). To many parents, 77 educators and policy makers, smaller classes are an apparently full-proof prescription for improving students‟ performance. That is fewer students means more individual attention from the teachers, calmer classrooms and consequently, higher test scores (Fall, 2003). The larger the class, the less time teachers spend on instruction, and the more time they spend on discipline or keeping order (Deutsch, 2003). The largest difference in achievement between students is that between students in different classes (Ken, 2001). Nye, Hedges and Konstantopowlos (2000), discovered that smaller classes (below 20) have positive effects on pupils academic performance. Blatchford et al., (2003) pointed out that small classes can encourage aspects of teaching that are the same as those identified in rReseYarch on effective teaching (e.g immediate feedback, sustaining purposeful interactions) lAinked with the promotion of pupils achievement. They explained that the connection may not Rnecessarily follow, that small classes will not make a bad teacher better, but small classes seemI Blikely to make it easier for teachers to be effective. Averest and Mclennan, (2011) reported a p oLsitive and significant effect of class size on children test scores for United State of AmericaN. They also reported a positive relationship between class size and test scores for Israel. For BAritain they reported that class size is not significant in explaining students‟ performance. In aDddition they reported that time series evidence suggests that class size reductions in the UnBitedA States over the last three decades have not led to improvements in students‟ performance. W oeIssman and West (2002), found significant effect of class size on mathematics or science testF scores. They found significant benefits to smaller classes for mathematics in France and o n OIceland and for science in Greece and Spain. It is one of the environmental contextual factor Ythat will influence teachers and pupils in a number of ways (Blatchford et al, 2003). WhileI TAverest and Mclennan (2011) concluded that Senior Secondary Students in small sized classSes show higher achievement in chemistry relative to their colleagues in large sized classes. R Hanushek (V200E3) wrote that there is no significant relationship between teacher-pupil ratio and student ouItcomes in developed countries. His analysis of studies involving developing countries shNows that almost half of the studies found no significant effect and the studies that are significaUnt are divided equally between positive and negative findings. He concluded that the weight of the evidence showed no consistent positive effect of reducing class size on students‟ outcome. Woessmann and West (2002) and Pong and Pallas (2001) observed positive and often significant class size effects in several different countries. Kokkelenberg et al., (2005) presented a theoretical model suggesting that the functional form of the relationship between class size and student achievement should be negatively sloped and concave. Even though there is now strong 78 evidence that smaller class size may improve student performance, at least in some circumstances, and using common methodologists to test the data. The debate continues in particular the economists point out the need to weigh the cost of achieving smaller classes versus the costs of improving student achievement by other means (Hanushek and Luque, 2003). There are significant disadvantages of large classes which include strained impersonal relations between students and the instructor, limited range of teaching methods, discomfort among instructors teaching large classes (Stanley and Porter, 2002). Extant research on the relationship between class size and students performance has identified conflicting results (Toth and Montagna, 2002). The results of some studies showed no significant relationship between claRss sYize and student performance according to Carpenter (2006), while other studies favoAur small class environments, the results vary based on the criteria used to gauge students‟ perfRormance as well as the class size measure. When traditional achievement tests are used, smallI cBlasses may provide no advantage over large classes. However if additional performance crite rLia are used (e.g. long term retention, problem-solving skills), it appears that small classes holdN an advantage (Aria and Walker, 2004). Blatchford et al., (2003) concluded that there is a lack ofA coherent theories by which to guide and interpret empirical work on class size effects and AwitDh which to make new predictions. The literature on class size, composition and studentsB‟ achievement is broad, diverse, diffuse and generally unwieldy. As one researcher has describ eId it that the outcomes of the research effort (into the connection between class six and educatioFnal attainments) have been conflicting, inconclusive and disappointingly meager (Fleming, et aOl 2002). Afolabi (2002) investigated sYchool factors and learner variables as correlates of senior secondary physics achievementI iTn Ibadan found no significant relationship among class size and students‟ learning outcomes.S On the other hand, Adeyemi (2008) worked on the influence of class size on the quality of ouRtput in senior secondary schools in Ekiti State, Nigeria found that schools having an averageV claEss size of 35 obtained better results than those having > 35. On investigating the effect of clIass size on students‟ achievement: evidence from Bangladesh, Asadullah (2005) concluded thNat reduction in class size in secondary grades is not efficient in a developing country like BanUgladesh. Thus the divergent view on the effect of class size on achievement continues. Based on the various controversial results of findings on the effects of class size on students achievement in science subjects especially chemistry, this study examined the relationship between class size and students‟ achievement in practical chemistry. 79 2.12 Appraisal of Literature Reviewed Researches show that in order to increase the level of attitude and success in science education, new teaching methods and technology need to be implemented in science education (Adesoji, 2008; Goner and Basaran 2008). Problem-solving is one of the most important issues in teaching and learning. The role of problem-solving in science is indispensable. It is an integral part of science. Science itself is a problem-solving subject. It is a subject that revolves around finding one solution or the other to some problems. Problem-solving should be the centre of instruction, and the way it is practiced must change, it should be a part of an active learning of the instructional process. When students know all the relevant facts and principles necessary for the soRlutiYon of a problem, they may be unable to solve it because they lack any systematic strategy foAr guiding them to apply such facts and principles (Gok and Silay, 2010). The notion of problemR-solving which is sometimes described as a core skill has received much attention in thIeB literature of science education. Unfortunately there is considerable diversity in seeking tLo describe what problem- solving actually is, ranging from descriptions of analytical proceduNres to statements like „What you do when you don‟t know what to do‟ (Rusbult, 2008). A Many tasks performed in professional and dAailyD life require problem-solving abilities. These tasks could range from designing a producBt, solving management problem, analyzing a scientific problem like discharge of poisonous ga seIs or predicting flooding in an ecological zone to opening a door with a jammed lock. TherefoFre incorporating problem-solving in science learning may be regarded as a step in the right dir eOction as it would equip students with relevant knowledge, skills and experience. Suggestions fYrom research are that instructional methods should take into account the general strategies aInTd methods of problem-solving, thus providing a tool to increase reasoning skills in the probleSm solver. Life is, in essence a continuous process of problem-solving and selection from avaiRlable and/or created options. Nevertheless, problem-solving abilities or decision making VcapEacities are valuable and precious skills not only in academia, but also in the world of busineIss and industry and in daily living. Furthermore, in science these skills play an important roNle in the acquisition and organization of knowledge in a meaningful way (Cardellini, 2006). TUhis shows the importance of chemistry process skills which is acquired during the performance of practical. Reports from research showed that students performed poorly in practical chemistry and they had poor quantitative skills. Therefore the research into chemistry process skills formed the basis for this study and it was discovered that they had significant effect on achievement in practical chemistry. 80 Few literature relating to problem-solving models in chemistry is available (Selvaratnam– Frazer, 1982). Some problem-solving models were designed to solve practical problems in science in which students were exposed to practical activities or learning tasks (West, 1992; Ige, 2003), while few were designed to help students develop laboratory skills (Onwioduokit, 1989; Ikitde, 1994). Cardellini (2006) discovered that many models have been used in teaching but still the performance of the students is still low. This necessitated the need for the researcher to develop a model that could be used to meet the needs, demands and complexities of practical, experimental and theoretical problem-solving in science. Reviewed studies show that the achievement tests scores of students are used aRs a mYeasure of not only the students‟ achievement but also the teachers‟ achievement, peArformance and effectiveness (Hudson, 2007). It was discovered from this study that treatmeRnts had significant effects on students‟ achievement in practical chemistry while Hands-on aInBd Minds-on Problem- Solving Model had the highest mean score. Researchers such as Jos hLua., et al (2006) and Berk (2005) were of the opinion that test based students‟ achievement Ngains have predictive power but provide little insight into both the teachers and the students‟A strengths and weaknesses, except factors such as students‟ attitude, classroom environment suDch as class size, teachers‟ qualification. This is the reason why this study looked into these factoArs and the researcher made sure the teachers in the researched schools are professionally qualif ieIdB. The attitude of a learner towards scieFnce would determine the measure of the learners‟ attractiveness or repulsiveness to scienc eO. This will invariably influence the learners‟ choice and even achievement in that subject (GYonen and Basaran (2008); Normah and Salleh, 2006). Adesoji (2008) maintained that problemI-sTolving strategy is probably a basic means of changing students‟ attitude towards science, thaSt the effect of solving problem on a student‟s attitude toward science is incredibly important beRcause problem-solving requires patience, persistence, perseverance and willingness to acVceptE risks. It was discovered from this study that treatments had no significant effect on studenIts‟ attitude to practical chemistry. This can be explained by the findings of Machina and GokhleyN (2009) that “maintaining the levels of positive attitude towards science in early years is easierU than transforming the negative attitude to positive attitude in the following years”. Festus and Ekpete (2012) wrote that recent reports on students‟ performance in chemistry show that the students still possess low attitudes towards problem-solving in chemistry. Class size is one environmental contextual factor that will influence teachers and pupils in a number of ways (Blatchford et al., 2003). The literature on class size, composition and students‟ achievement is broad, diverse, diffuse and generally unwieldy. As one researcher describes it as the 81 outcomes of the research effort have been conflicting, inconclusive and disappointingly meager (Fleming et al., 2002). Parents and educators almost universally identify small classes as a desirable attribute of successful school systems and class size reduction initiatives have been implemented widely. Despite this and decades of study, researchers remain divided on whether smaller classes actually have positive effects on students‟ outcome and/ or whether the magnitude of the effect justifies the high cost of implementing class size reductions. A larger debate focuses on whether increasing resources to schools in any way improves students‟ outcome. This discussion is being carried out throughout the world, with some different frame works between developed and developing countries. In developed countries wheRre aYccess to primary and secondary education is essentially universal but the quality is varied, Aresearchers are concerned with identifying specific treatments to improve students‟ outcomesR, such as reduced class size, increasing teachers‟ salaries, or expanding teacher education. DIeBveloping countries are often still dealing with the tradeoff between increasing access to ed uLcation and improving the quality of existing education. Improving quality in this context caNn mean providing textbooks and adequate facilities, more fundamental needs than are the focus iAn the developed world (Averest, and Mclennan, 2011). D Due to these the researcher developed a modelA Hands-on and Minds-on Problem-Solving Model (HAMPSOM) which combines both theor eItiBcal and practical aspects of science as opposed to the separate theoretical and practical mFodels found in literature, incorporating intensive theoretical background and teacher guid eOd discovery learning. This study examined the extent to which the models (HAMPSOM) andY (LAPSOM) using the instructional guides improved students‟ attitude to and achievement in pIrTactical chemistry. It further determined the moderating effects of level of possession of chemisStry process skills by the students and class size. R IV E UN 82 CHAPTER THREE 3.0 METHODOLOGY This chapter deals with Research Design, Population of the Study, Sample and Sampling Techniques, Instrument and Instrumentation, Data Collection and Data Analysis Procedure. 3.1 Research Design A quasi experimental design was used for this study. A 3x2x2 non randomised control group pretest and posttest design was adopted. Y The layout of the research design is as follows: R E1 O1 X1 O2 A E2 O1 X2 O2 R C O1 X3 O2 where LI B E1 represents experimental group 1 N E2 represents experimental group 2 A C represents control group AD O1 represents pretest scores of the expBerimental and control groups O2 represents posttest scores ofF the Iexperimental and control groups X1 represents experimental treatment with Laboratory Problem-Solving Model (LAPSOM) instructio nOal guide X2 represents expeTrimYental treatment with Hands-on and Minds-on Problem-Solving Model (HAMIPSOM) instructional guide X3 repreRsentSs conventional method of teaching for the Control group IV E N U 83 3.2 Factorial Design The 3x2x2 non randomised factorial design is shown below Table 3.1: 3x2x2 Factorial Matrix TREATMENT CLASS SIZE LEVEL OF SKILL POSSESSION H L Y L R E1 S RA L IB E2 S L L N C S DA A E1 represents experimental treatment with ILBaboratory Problem-Solving Model (LAPSOM) instructional guide. F E2 represents experimental treatm Oent with Hands-on and Minds-on Problem-Solving Model (HAMPSOM) insYtructional guide. C represents teaching wIitTh the conventional method as control. S represents small cSlass size with number of students 40 and below. L represents larRge class size with number of students 41 and above. th H represeVntsE students with high scores above 50 percentile. th L repreIsents students with low scores below 50 percentile. N 3.3 VUariables of the Study Independent Variables Teaching at three levels. a Laboratory Problem-Solving Model (LAPSOM) b Hands-on and Minds-on Problem-Solving Model (HAMPSOM) c Conventional Method as control Intervening (Moderator) Variables. 84 a Chemistry Process Skills b Class size Dependent Variables. a Students Attitude to Practical Chemistry b Achievement in Chemistry 3.4 Population. This comprised of intact class of S.S 2 chemistry students from three educational zones in nine local government areas and nine public schools in Oyo state as shown in Table 3.3. TablRe 3.2Y shows the Educational Zones with the number of Local Government Areas and number oAf Public Senior Schools in each zone. R IB Table 3.2: The distribution of Public Senior Secondary Schools acr osLs the Eight Educational Zones in Oyo State. N A No of Public Senior No. of Local Govt. Areas Educational Zones D Secondary Schools Ibadan Municipal 5 BA 81 Ibadan Less City 6 I 110 Ibarapa 3F 19 Ogbomoso O 5 64 Oyo Y 4 38 Saki IT 3 33 Irepo S 3 14 Kajola ER 4 50 Total V 8 33 409 SourNce: SItatistics Department, Ministry of Education, Oyo State. (2012) U 85 Table 3.3: Sampling Distribution Educational Local Selected Local No. of No. of Students Zone Government government Schools chosen 1 Ibadan Ibadan North Ibadan North 1 IntactClass(Expt1) Municipal Ibadan N East -- -- (58) -- R Y Ibadan S West Ibadan S West 1 IntactCAlass(Expt2) Ibadan S East -- -- (65R) -- Ibadan N West Ibadan N West 1 IBIntactClassControl L (33) Ibadan Less Lagelu L a g e l u 1N IntactClass(Expt1) city Egbeda -- A -- (36) -- Akinyele Akinyele AD 1 IntactClass(Expt2)Ona-Ara -- B -- (49) -- Oluyole Oluyo lIe 1 I n t a c t C l a s s ControlF (31) 3 Oyo Afijio OAfijio 1 IntactClass(Expt1) Oyo West Y -- -- (65) -- Atiba IT Atiba 1 IntactClass(Expt2) S (40) Oyo East Oyo East 1 IntactClass ER (Control) (62) TOTAL I V03 14 09 09 5 Large C.S = 299 N 4 Small C.S =140 U Total = 439 3.5 Sampling Technique and Sample School Sample Multi-Stage sampling technique was used to select schools that participated in the study. At the first stage, the names, number of local government areas and the number, names of secondary 86 schools in the eight educational zones, were obtained from the Ministry of Education. Also schools approved by the West African Examinations Council (WAEC), to register and prepare students for the West African Senior School Certificate Examination (WASSCE) in chemistry for at least five academic sessions were obtained. The second stage involved the sampling of three educational zones and nine local government areas based on their geographical location, so as to avoid experimental contamination. The third stage involved stratification of schools from the list of eligible schools in the first stage in the nine local government areas. To ensure comparability of schools, each school eligible for selection was based on: RY (1) Availability of the basic chemistry apparatus needed for the study, by adAministering the Laboratory Inventory Check List (LICL) developed by the researcheRr for the teachers. (See APPENDIX VII). IB (2) Availability of a professionally qualified chemistry teacher fLor at least three academic sessions. N (3) Willingness of the principal to allow the research to bAe carried out in the school. (4) Cooperation of the chemistry teacher and willingnDess to participate in the research. The fourth stage involved the selection of nine schoAols (sample) which was done by stratified sampling of the eligible schools on the basis of IgeBographical location. The study samples were reasonably spaced from each other, and no scFhool had more than one treatment condition so as to avoid experimental contamination. The t hOree schools in each local government area were randomly assigned the two treatment conditions ITY and control. Students' Sample S These were all the S.SR 2 students offering chemistry as one of their WASSCE subjects in the nine schools. Since claVsseEs in Senior Secondary Schools (S.S.S) in Oyo state were grouped into Science, Art and CommeIrcial classes. In each of the selected schools an intact class of chemistry students in the science Nclass with a total 439 students in the nine schools participated in the study. This is because Uit is only the science students that offer chemistry. 3.6 Instrumentation Three instruments were used in this study. These are: (1) Chemistry Achievement Tests. (CAT) (2) Students‟ Attitude to Practical Chemistry Scale. (SAPCS) 87 (3) Chemistry Process Skills Rating Scale (CPSRS) Three Stimulus Instruments were used. These are: (1) Laboratory Problem-Solving Model (LAPSOM) Instructional Guide. (2) Hands-on and Minds-on Problem-Solving Model (HAMPSOM) Instructional Guide (3) Conventional Method Instructional Guide as control. (1) Chemistry Achievement Test. (CAT) This is a 70-multiple choice item with four options A to D. Students supplied the correct answer. The content validity was established using the scheme of work for chemistry by the Ministry of Education Oyo State to develop the items across the cognitive domain usinRg BYloom‟s taxonomy. The table of specification of the selected items is shown in Table 3.4.A The difficulty levels of the items were determined. Thirty items with difficulty level ranging bRetween 0.5 and 0.6 were selected (APPENDIX V11). The test items were trial tested on 140 SI.SB 2 students in schools not taking part in the study in Ibadan North Local Government Area o fL Oyo State. In the scoring, each correct option selected attracted one mark while every wrong Nanswer attracted zero mark. The answers are in APPENDIX V111. Kuder Richardson formula 2A0 (KR-20) was used to establish the internal consistency of the instrument, a reliability valueA of 0D.79 was obtained for the test items. Table 3.4: Table of Sp ecIiBfication F CONTENTS O COGNITIVE LEVELS KNOWLTEDY COM PREH APPLICATIO ANAL SYNTH EVALU TOTA TOPICS GE I ENSI N YSIS ESIS ATION L ON Nature of matter: R 3, 5S, 7 9, 11 1, 2 4, 6 ,8, 10 physical and chemical (03) (10.0%) changes, elementsE (02) , (05) (16.7%) (33.3%compounds and (6.7%) ) mixtures. V Determination oIf the empiricaUl foNrmula of Magnesium oxide. Separation technique: 17, 18, 19, 22, 25, 16,30 12, 13 29 17 sublimation, 20, 21, 23, (4) (13.3%) (02) (01) (56.7% filtration, 24, 26, 27, evaporation, 28, (6.7%) ) (3.3%) separation funnel (10)(33.3%) method. Volumetric analysis 15 10 14 03 (01) (3.3%) (01) (10.0% 88 (3.3%) (01) ) (3.3%) TOTAL 13 02 10 03 02 30 43.3% 6.7% 33.3% 10.0% 6.7% 100% (2) Students’ Attitude to Practical Chemistry Scale (SAPCS) This is a thirty item instrument. It was developed by the researcher with a 4- point Likert rYesponse options of Strongly Agree (SA), Agree (A), Disagree (D) and Strongly Disagree R(SD). (See APPENDIX 1X). It is concerned with finding out students‟ attitude to pRrobAlem-solving in chemistry. Two procedures were adopted in the establishment of the validity Bof the instrument. Two lecturers from the Institute of Education, University of Ibadan, assessed LtheI instrument and found it satisfactory in terms of content, clarity of expression and purposeN of study. The thirty items were trial tested on 140 S.S 2 science students in Ibadan North LocalA government area, a group similar to those whom it is intended but did not form part of the samDple. The Cronbach alpha statistics was preferred because it measures internal consistency of Aitems and also the construct validity. The scoring was based on Likert scale of measurem enItB: Strongly Agree (4), Agree (3), Disagree (2), Strongly Disagree (1) for items on the scalFe indicating positive attitude to chemistry problem solving. Scoring was reversed for it emOs indicating negative attitude. The maximum score obtainable for SAPCS was one hundYred (100). In order to categorize the students, their scores were standardized. Grouping was T Below -1 Standard DIeviation (S.D) = Low attitude. Above +1 StRandSard Deviation = High attitude. The reliability estimaEte using Cronbach alpha coefficient was found to be 0.85. IV (3) ChemNistry Process Skills Rating Scale (CPSRS) ThUis instrument was adapted from A Scale For The Assessment of Students‟ Chemistry Practical Skills In Secondary Schools by Njoku (1999). It is a 5-point rating scale (Very Poor, Poor, Fair, Good, Excellent) containing 8 scale skill categories. Among these skill categories 57 skill items called behaviour categories were unevenly distributed. The researcher used 7 scale skill categories and 39 skill items for this study. (See APPENDIX X1) The researcher re-validated the instrument using two schools that did not take part in the study. The validity of CPSRS was 89 assessed and judged as adequate by experts based in chemistry teaching. The inter rater reliability of CPSRS was estimated as 0.78 using Scott Pie method. 2 Scott Pie =P0 - Pe Where PO = 100- (% Difference), Pe = (% Average) 100 - Pe 100 The ratings were: Very poor = 1, Poor = 2, Fair = 3, Good = 4, Excellent = 5. 3.7 Procedure for the Study RY The following steps were adopted: A  An official letter of introduction of the researcher and the study was obtaineRd to the principals of the selected schools from the Institute of Education, University of IIbaBdan. Ibadan.  The principals concerned were met individually for dialogue on th eL purpose, procedure of the study and official permission was obtained. N  The chemistry teachers of the selected schools for the stuAdy were met and intimated with the objectives of the study they served as the research assistDants throughout the study. They did the main teaching using the treatment aBssigAned to their respective schools.  The research assistants were trained based o nI the treatment assigned to their school and the use of the Chemistry Process Skill RatinFg Scale (CPSRS) for two weeks.  The chemistry students were met an dO i discussed the need for their cooperation during the study. Y  The pre test Students‟ AttitIuTde to Practical Chemistry Scale (SAPCS) was administered to the studSents by the research assistants and the researcher monitored the administration of tRhe test.  The pre testV ChEemistry Achievement Test (CAT) was also administered to the students.  The stNudenIts were observed during titration of an acid (HCl) against a base (NaOH). They wereU observed individually by the research assistants in each of the schools, using Chemistry Process Skills Rating Scale (CPSRS) for the pretest.  The students were exposed to the treatments by the research assistants in the selected schools and the researcher monitored the administration of the treatments, for six weeks.  The post tests of both the SAPCS and CAT were administered to the students after the treatments. 90  The students were observed during titration of an acid (HCl) against a base (NaOH). They were observed individually by the research assistants in each of the schools using the Chemistry Process Skills Rating Scale (CPSRS), for the posttest. 3.8 Treatment Procedure This part was designed to operationally (operational phase) enable the teaching and learning of problem-solving in practical chemistry, it specified in clear terms what the teacher and the students are expected to do at each step of the process. The procedures for each of the two model instructional guides were followed as stated below for the two treatment groups. AR Y Treatment Group 1: Laboratory Problem-Solving Model (LAPSOM OpeRrational Teaching and Learning of Problem Solving (Instructional Guide) (See Appendix IIAB, IB, IC). The teacher teaches the theory during a period and the student s Lperform the experiment or the practical during another period, usually a double period. The stuNdents use the laboratory manual which is an extract from the instructional guide and contains onAly the steps that the students follow during the experiment prepared by the teacher. The tAeacDher is present with the students as an observer. IB Stage1- Recognize the Problem F Actions (a) Read carefully the la bOoratory manual. Identify the practical problem posed and recognize the apparatus provided. ChYeck the soundness of the apparatus (b) Write down the problem andI sTub-problems that require solution (a problem may be in the form of a statement or a question oSr the aim of an experiment). (c) Read the instructionR or question again; sketch a diagram of how you intend to arrange the apparatus to enabVle yEou solve the problem. I Stage2 (A) N Recall background information Actions U(a) Write down known general principles and mathematical expressions that are necessary for solving the problem. (b) List possible sources of error in solving the problem. (c) Recognise independent and dependent variables in the problem as explained by the teacher during the theory period and note the relationship between them. 91 (d) Re-arrange the mathematical model or expression in a simple form, making the required quantity the subject of the expression. Stage 2(B) Predict tentatively Actions: (a) Predict the relationship between variables the nature of the graph and the intercept (if any) (b) Predict the solution to the problem Stage 2(C) Draw up table for data Y Actions: In view of the anticipated solution to the problem, draw up a table for dataR, providing appropriate units. RA IB Stage 3A: Experiment L Actions (a) read the questions again N (b) Together with the sketched diagram in stage 1 step c, set upA the apparatus to solve the problem. (c) Take precautions on the basis of the supposed errors D (d) Manipulate the independent variable to obtain the coArresponding value of the dependent variable (where applicable). Repeat the process with at le aIstB four other different values of the independent variable. Write the values straight into the tablFe already drawn in stage 2c above. O Stage3B: Predict from data Y Actions: inspect the data obtaineIdT and make more realistic predictions based on the data to include: (a)Nature of the graph S (b)Position and naturEe ofR intercept when the independent variable is zero, the dependent variable could have a vValue other than zero. (c)Solution of alIl the problems N Stage 4:U Analyze the data 4(A) Graph Actions: (a) Note the smallest and the largest values of the dependent and independent variables respectively, the size of your graph paper and then choose appropriate scales. Plot the values on the graph paper. (b) Draw the best straight line or curve through the points. 92 Stage 4(B) Calculations Actions: (a) find the slope and /or the intercept from the graph and relate them to the mathematical expression given or derived. (b) Calculate all required values using the mathematical expression and the plotted graph Stage 5(A) Evaluate your solution Actions: (a) find the average values of both dependent variables (b) Substitute these values and those obtained from the graph into the mathematicalR expYression derived or given. A (c) Solve the equation to see whether or not the two sides are equal. R LI B Stage 5 B: Evaluate your experiment N Actions: (a) is your equation balanced? Why? A Write down the importance of the problem solved D (b) What can you conclude from the experiment (soBlutAion to the problem) and what do you think could be done to improve the solution to the probl eIm? In cases when the required solution was not obFtained, the steps were reversed. Students answer the questions at the end oOf each topic. NOTE Some stages may be missiTng Yin some experiments that do not involve variation of variables and plotting of graph(s), whiSch tIhe teacher would have explained during the theory period. Treatment Group 2: RHands-on and Minds-on Problem-Solving Model (HAMPSOM) Operational TeIaVchi Eng and Learning of Problem-Solving (Instructional Guide) (See Appendix IIA, IIB, IICN). BotUh the teacher and the students are involved in performing the experiment and the practical. The teacher teaches the theory actively involving the students and guides them to perform experiment or practical during the same period. Incorporating the experiments and the practical into the theory lesson, there is no separate period for theory or performing experiments/ practical. STEP 1A: Problem Perception. a. The teacher writes the problem in form of a question or a statement 93 The students: a. Read the problem statement or question carefully. b. Think about it c. Write down what you want to find out. Teacher goes round to see what they have written. STEP 1B: Acquiring Related Theory. a. The teacher teaches the students the related theory RY STEP 1C: Planning Experiment. A a. The teacher draws diagram R The students: IB a. Write down the apparatus. L b. Select the apparatus. N The teacher supervises them, renders help where nAecessary D STEP 2A: Recalling Theory. A The students: IB a. Write down the laws and the equFations. b. Write down the procedure foOr the experiment. c. Draw the necessary tabYles f or the experiment. The teacher supeIrvTises them, renders help where necessary S STEP 2B: Performing ERxperiment or Practical The studenEt: a. SeIt Vup the apparatus as in the diagram. bN. Carry out the experiment. U c. Make measurements. The teacher supervises them, renders help where necessary STEP 3A: Making Observations. The students: a. Write down the observations made from the experiment 94 The teacher supervises them, renders help where necessary STEP 3B: Recording Data. The students: a. Write down measurements and observations in form of tables. b. Put the correct units The teacher supervises them, renders help where necessary STEP 4A: Analysing result. RY The students: A a. Use the formula given in the theory or derived to analyse the result.R b. Plot the graph IB The teacher supervises them, renders help where necessary L AN STEP 4B: Interpreting and drawing conclusion. D The students: A a. interpret the result obtained in 4A I B b. Draw conclusion. F If the required result is not ob taOined c. Recall theory Y d. With the assistance Tof the teacher they can change the technique e. Perform the exSperiIment again. If the requiredR result is suspected to have been obtained, the students proceed to step 5A E STEP 5A: EvalIuaVtion of method and result aN. Evaluation of the methods. Ub. Evaluation of the results. The teacher supervises them, renders help where necessary STEP 5B: Consolidating Knowledge Gains. a. Check if conclusion is in line with the aim of the experiment. b. Check if the results are the required ones or not 95 With the assistance of the teacher If the conclusion is in line with the aim of the experiment and the results are the required ones the problem stated in 1A is solved. If these are not the required ones then the students proceed to step 5C. STEP 5C: Change in Technique. a. If the conclusion is not in line with the aim (solution to the problem) or the result is not the required one. b. Change the design or technique, with the assistance of the teacher. RY The teacher allows them to ask questions at the end of each step. A Students answer the questions at the end of each topic. BR LI N DA Control Group. A This group followed the conventional mIeBthod of teaching. Administration of pretest, posttest of Chemistry Achievement Test (CAFT) and Student Attitude to practical chemistry scale were be done by the research assistants. O The teacher used the instructional guiYde to teach the students. (See Appendix IIIA, IIIB, IIIC). T 3.9 Data Collection SI The chemistry teRachers of the selected schools were the research assistants who assisted in the administration aEnd supervision of the pretest and posttest of Chemistry Achievement Test (CAT) and StuIdVents‟ Attitude to Practical Chemistry Scale (SAPCS) and collection of these instruments Nfrom the students before and after the administration of the treatments. Observation of the studeUnts (before and after) using the Chemistry Process Skills Rating Scale (CPSRS) was done by the research assistant in each school used for the research. The researcher went round and ensured proper administration of the instruments. 3.10 Data Analysis 96 The statistical tool used to establish both the main effect and interaction effect of the independent variables on the dependent variables for this study is Analysis of Covariance (ANCOVA). Scheffe pairwise post hoc analysis was used to determine the direction and magnitude of the mean difference between the groups and the level of significance. 3.11 Methodological Challenges Despite the fact that availability of apparatus was one of the criteria for selection of the schools used for the research, the researcher still took some apparatus to some of these schools. In most of the schools the number of periods for chemistry has been reduced to three perioRds Ybecause of the increase in the number of subjects offered by the students, this is not adequateA especially the single period is too short for the teachers and the students to perform experimenRts or practical. No laboratory attendants in the schools used for the research. IB L N AD A F I B O TY RS I IV E UN 97 CHAPTER FOUR 4.0 RESULTS AND DISCUSSION This chapter presents the results of data analysis and the discussion of the findings. The data collected were subjected to Analysis of Covariance (ANCOVA). The level of significance, for the interpretation of the results was set at p < 0.05. The results are hereby presented in line with the order in which the hypotheses were stated in Chapter One. Y 4.1 Testing the Hypotheses R 4.1.1 Ho1a: There is no significant main effect of treatments on students’ attiRtudeA to practical chemistry. In order to test the significance of the main effect of treatments (ExLp II, EBxp II and Control) on students‟ attitude to practical chemistry, a 3 x 2 x 2 ANCOVA teNst w as run. Table 4.1 shows the Composite table for the ANCOVA Tests. A From Table 4.1 it is clear that treatments had noA sigDnificant effect on students‟ attitude to 2 practical chemistry. F(2, 346) = 2.97, p > 0.05, partial η = 0.017. The effect size (1.7%) of treatment on attitude was low. Based on this result, the nu llI hBypothesis (Ho1a) was not rejected, that is the students‟ attitude is not affected by the treatmeFnt. Y O Discussion The result of this study showITs that treatments had no significant effect on students‟ attitude to practical chemistry. In suppSort of this result is the view of Machina and Gokhley (2009) that “maintaining the levelsR of positive attitude towards science in early years is easier than transforming the VnegEative attitude to positive attitude in the following years”. This implies that the students‟ attitudIe to practical chemistry is already formed in the higher class (S. S. Two) used for this study. NFestus and Ekpete (2012) wrote that recent reports on students‟ performance in chemistrUy show that the students still possess low attitudes towards problem-solving in chemistry. The result of the present study is contrary to the findings of other researchers such as Gok and Silay (2010), who worked on the effects of directive and non directive problem-solving on attitude and achievement of students in a developmental science course; the result is that attitude becomes more positive after instruction. Popoola (2002) and Udosoro (2000) reported that students 98 tend to show more positive attitudes after being exposed to self learning strategy such as computer and text assisted programmed instruction, self learning device and self instructed problem based. Table 4.1: Test of between sample ANCOVA for the effect of treatments on students’ attitude to practical chemistry Source Type III Sum Df Mean square F Sig Eta Of squares squared RY Corrected Model 1826.353 12 152.196 1.984 .025*A .064 BR Intercept 27681.75 1 27681.725 360.9 2L9 I .000* .511 N PREATTIT 1.852 1 1.852 A .024 .877 .000 AD TREAT 455.099 2 I 2B27.549 2.967 .053 .017 F SIZE 164.203 1 O 164.203 2.141 .144 .006 Y SKILL 231.70S3 I T 1 231.703 3.021 .083 .009 R TREAT*SKILL V E507.099 2 253.549 3.306 .038* .019 I TREATU * SNIZE 28.026 2 14.013 .183 .833 .001 SIZE * SKILL 69.153 1 69.153 .902 .343 .003 TREAT * SIZE* SKILL 118.353 2 59.176 .772 .463 .004 99 Error 26536.745 346 76.696 Total 3004519.000 359 Y AR LIB R Corrected Total 28363.097 358 AN R Squared = .064 (Adjusted R Squared = .032) D Hunt, Haidet, Coverdale, and Richards (2003) noteBd fAI avourable student‟s attitude towards active learning methods. Also several studies such as Gonen and Basaran (2008); Ajzen and Fishbein (2000) and Wilson, Ackerman and Malave (20F00), reported that students‟ positive attitude towards science probably correlate highly with thOeir achievement in science. Normah and Salleh (2006) indicated that students‟ attitude aTnd Yinterests could play a substantial role among pupils studying science. I Although there was Sno significant effect of treatment on attitude, there is the need to examine the pre, posEt anRd the mean of students‟ attitude scores. Table 4.2 presents the means of each of the treatmVent groups‟ scores on attitude. I UN Table 4.2: Estimated marginal means for Post student’ attitude to practical chemistry score. 95% Confidence Interval for Difference 100 Treatment Mean Std. Error Lower Bound Upper Bound EXP 1 91.396 .796 89.832 92.961 EXP 2 93.023 1.007 91.042 95.004 CONTROL 89.810 .860 88.119 91.502 Evaluated at covariates appeared in the model: PRE ATTITUDE SCORE = 86.7549. Table 4.2 shows that students in the Experiment 2 had highest mean score (93R.02)Y in the students‟ attitude to practical chemistry while students in the control group had lowAest mean score (89.81). This shows that Experiment 2 involved the students more in problemR-solving activities than the other groups. This buttressed what Sule (2000) said that there isI Bthe need to advance a variety of teaching methods, having to do with heuristic problem-s oLlving in order to promote positive attitude of students. N A 4.1.1 Ho1b: There is no significant main effect of treaAtmDents on students’ achievement in practical chemistry A 3 x 2 x2 ANCOVA test was run in or dIeBr to test the significance of the main effect of treatments (Exp I, Exp II and Control) on studFents‟ achievement in chemistry. Table 4.4 shows the Composite table for the ANCOVA Tests . O From Table 4.4 it is clear that treIaTtmeYnts had significant effect on achievement in chemistry, F(2, 346) 2= 13.03, p < 0.05, partial Sη = 0.070. The effect size (7.0%) of treatment on the chemistry achievement test was higRh. Based on this result the null hypothesis was rejected. E Discussion V AccordiNng tIo the result of this study, the treatments had no significant effect on the attitude of the studeUnts to practical chemistry but had significant effect on achievement in practical chemistry. This shows that attitude of the students had no effect on their achievement. This may imply that attitude had no effect on achievement. This is in agreement with Babatunde (2001)‟s finding that the achievement of secondary school students in solving word problems in mathematics and physical sciences could be enhanced through problem-solving. 101 Having established that there was significant effect of treatments on achievement in chemistry, there is the need to examine which treatment produced the highest mean score in achievement. Table 4.3 presents the mean score of each of the treatment groups‟ in chemistry test items. It shows that students in the Experiment 2 had highest mean score (20.02) in chemistry achievement test, while students in the control group had lowest mean score (15.09). Discussion This result shows that Experiment 2 students had more knowledge in both theoRretiYcal and practical aspects than the other groups, since both aspects were teacher and studentAs directed. The result is in support of Senocak, Taskesenligil, and Sozbilir, (2007)‟s findinRgs that, there is a statistically significant difference between the problem-based learning andI cBonventional groups in terms of their achievement, attitude towards chemistry, skill de vLelopment and conceptual understanding. AN Table 4.3: Estimated marginal means for Posttest AcAhieDvement in Chemistry Score I B 95% Confidence Interval O F for Difference Treatment Mean Y St d. Error Lower Bound Upper Bound EXP 1 18.604 TS I .620 17.384 19.824 EXP 2 20.0R19 .929 18.191 21.847 CONTROL I V 1 E5.091 .775 13.566 16.615 Evaluated atN covariates appeared in the model PRE CHEMISTRY SCORE = 19.7103. U 102 Table 4.4: Test of between sample ANCOVA for main effect of Treatment Groups on Posttest Achievement in Chemistry Scores Source Type III Sum Df Mean square F Sig Eta Of squares R sqYuared A Corrected Model 4106.161 12 342.180 7.371 I B . R000* .204 L Intercept 2077.478 1 2077.478 4N4.751 .000* .115 A PRECHEM 529.842 1 529.A842D 11.413 .001* .032 IB TREAT 1209.540 2 F 604.770 13.027 .000* .070 O SKILL 471.243 T Y 1 471.243 10.151 .002* .029 SI SIZE 674R.845 1 674.845 14.537 .000* .040 VE TREAT*SKNILLI 474.463 2 237.231 5.110 .006* .029 U TREAT * SIZE 97.544 2 48.772 1.051 .351 .006 SIZE * SKILL 1000.136 1 100.136 2.157 .143 .006 103 TREAT * SIZE* SKIL 32.694 2 16.347 .352 .703 .002 Error 16062.323 346 46.423 Total 121318.000 359 Y RA R B N LI A Corrected Total 20168.485 358 D R Squared = .204 (Adjusted R Squared = .176) A B Table 4.5 shows the Scheffe Pairwise PoFst H oIc Analysis on Treatment Groups and Control in Achievement in Chemistry Score from thOis table Experiment 2 students had a mean difference of 1.42 greater than students in experiment 1 and 4.93 greater than students in the control group. The experiment 1 students had a meTan Ydifference of 3.51 greater than the control group students in achievement in chemistry scoresI. ER S IV UN Table 4.5: Pairwise Comparisons Post Hoc Test on Treatment Groups and Control in Achievement in Chemistry Score. 95% Confidence Interval 104 for Difference (I)Treatment (J)Treatment Mean Std. Sig. Lower Bound Upper Bound Difference Error EXP 1 EXP 2 -1.415 1.099 .486 -4.053 1.222 CONTROL 3.513 .977 .001 1.170 5.857 EXP 2 EXP 1 1.415 1.099 .486 -1.222 4.05Y3 CONTROL 4.929 1.034 000 2.447 A 7R.411 CONTROL EXP 1 -3.513 .977 .001 -5.857B R -1.170 I EXP 2 -4.929 1.034 .000 -L7.411 -2.447 Mean difference is significant at p< .05 AN Table 4.6: Pairwise Comparisons Post Hoc Test on TAreatDment Groups and Control in Achievement in chemistry Score LevIeBl of Significance E1 OF E2 C E 1 Y * E2 S I T * C R * * IV*= E Significant difference There aUre sNignificant differences between Experiment 1 and 2 students and the control group students as shown in Table 4.6, but there is no significant difference between the students‟ achievement scores of the two experimental groups. 4.1.2 Ho2a: There is no significant main effect of level of possession of chemistry process skills on students’ attitude to practical chemistry 105 The significance of the main effect of level of possession of skill (High and Low) on students‟ attitude was tested, a 3 x 2 x 2 ANCOVA test was run. Table 4.1 shows the Composite table for the ANCOVA Tests. From Table 4.1 it is clear that possession of chemistry process skills had no significant effect 2 on students‟ attitude. F(1, 346) = 3.02, p > 0.05, partial η = 0.009. The effect size (0.9 %) of skill on attitude was very low. This shows that the null hypothesis was not rejected. Discussion The result of this study shows that chemistry process skills did not affect the studenRts‟ Yattitude to practical chemistry, so skilled and unskilled students displayed similar attitudes.A Therefore the investigation of students‟ attitude, behaviours, problem-solving knowledge Rand skills become important while solving a problem (Erdemir, 2009). IB Although there was no significant effect of skill on attitude, ther eL is the need to examine the mean students‟ attitude scores. Table 4.7 presents the mean ofN each of the groups‟ scores in students‟ attitude. It shows that students having low skill had higAher mean score of 92.31. D Table 4.7: Estimated marginal means for ChemistBry AProcess Skills on Post Students’ Attitude to Practical Chemistry Sco rIe. F O 95%Confidence Interval T Y for Difference I SKILL Mean SStd. Error Lower Bound Upper Bound HIGH 90.508E R .817 88.901 92.116 LOW 92I.V311 .633 91.066 93.556 EvaluateUd atN covariates appeared in the model: PRE ATTITUDE SCORE = 86.7549 Table 4.8: t- test for Chemistry Process Skills against Post Students’ Attitude to Practical Chemistry Score SKILL N M e a n S t d D eviation Std Error 106 Mean POST ATTITUDE HIGH 136 90.1250 8.7003 .7460 SCORE LOW 223 91.6143 8.9937 .6023 Table 4.8 also shows that students with low skill had higher mean of 91.61 and students with high skill had mean of 90.13. This also shows the effectiveness of problem-solving strategy. 4.1.2 Ho2b: There is no significant main effect of level of possession of chemistry procesYs skills on students’ achievement in practical chemistry R A 3 x 2 x 2 factorial ANCOVA test was run in order to test the significanAce of the main effect of chemistry process skills (High and low) on students‟ achievement in pRractical chemistry. Table 4.4 shows the Composite table for the ANCOVA Tests. IB From Table 4.4 it is clear that chemistry process skills had significa nLt effect on achievement in 2 practical chemistry, F (1, 346) = 10.15, p < 0.05, partial η = 0.02N9. The effect (2.9%) of skill on chemistry achievement test was moderate. This shows that the Anull hypothesis was rejected and the alternative hypothesis accepted. AD Discussion IB This result shows that chemistry process skFills had significant effect on achievement in practical chemistry despite the fact that there was nOo significant effect on attitude to practical chemistry. This also shows that attitude has no effecYt on achievement. This result is in agreement with Akale and Usman (1993)s‟ observation thaIt Tthe mental processes and skills associated with science can only be acquired and developedS when students actually participate in science instruction through practical experience, espRecially as practical work has been shown to improve student‟s attitude towards science kVnowEledge which could influence positive achievement in science. Having eIstablished that there was significant effect of possession of skill on achievement in chemistry, Nthere is the need to examine which group produced the higher mean score in achievemUent. Table 4.9 presents the mean score of each of the groups‟ in chemistry test items. Table 4.9: Estimated marginal means for Chemistry Process Skills for Post Achievement in Chemistry Score 107 95%Confidence Interval for Difference SKILL Mean Std. Error Lower Bound Upper Bound HIGH 21.374 1.467 18.488 24.260 LOW 14.435 .856 12.751 16.119 Evaluated at covariates appeared in the model PRE CHEMISTRY SCORE = 19.7103. Y RA R Discussion IB The result from table 4.9 shows that students with high cheNmis tr Ly process skill had higher mean score (21.37) in chemistry achievement than students witAh low chemistry process skill, mean score (14.44) in spite of their slightly higher attitude score. This shows that students with high chemistry process skills performed better than those AwitDh low skill, which further shows that attitude had no effect on achievement. This is alsBo shown in tables 4.10a and 4.11 where the students with high skills had higher mean differ enIce of 6.94 and mean 17.26 respectively. While Table 4.10b shows that both are significanOt. F Table 4.10a: Pairwise ComparisonYs Post Hoc Test on Chemistry Process Skills in post Achievement in CIhTS emistry Score. E R 95%Confidence Interval I V for Difference (I)SKILUL N (J)SKILL Mean Std. Error Sig Lower Upper Difference Bound Bound HIGH LOW 6.939 2.178 .002 2.655 11.222 LOW HIGH -6.939 2.178 .002 -11.222 -2.655 Mean difference is significant at p< .05 108 Table 4.10b: Pairwise Comparisons Post Hoc Test on Chemistry Process Skills in post Achievement in Chemistry Score Level of Significance H L H * L * Y *= Significant difference R A R LI B AN AD Table 4.11: t- test for Chemistry Process Skills agBainst Post Achievement in Chemistry Score F I SKILL Y O N M e a n S t d D eviation Std Error Mean POST ATTITUDE HSIGIH T 136 17.2574 7.4337 .6374 SCORE R LOW 223 16.4978 7.5515 .5057 VE 4.1.3 Ho3a: ThIere is no significant main effect of class size on students’ attitude to practical U N chemistry In order to test the significance of the main effect of class size (Large and Small) on students‟ attitude a 3 x 2 x 2 ANCOVA test was run. Table 4.1 shows the composite table for the ANCOVA Tests. From Table 4.1 it is clear that class size had no significant effect on students‟ attitude, F(1, 2 346) = 2.14, p > 0.05, partial η = 0.006. The effect size (0.6 %) of class size on attitude was very low. Based on this result the null hypothesis was not rejected. 109 Discussion The result shows that class size whether large or small had no significant effect on students‟ attitude to practical chemistry. In support of the result of this study, Blatchford et al (2003) also found no statistically significant differences between class sizes for most teachers‟ activities. Machina and Gokhley (2009) were of the view that “maintaining the levels of positive attitude towards science in early years is easier than transforming the negative attitude to positive attitude in the following years”. This may be the reason why the treatments, level of possession of chemistry process skills and class size had no significant effect on students‟ attitude to practical cheRmisYtry. Although there was no significant effect of class size on students‟ attitude, thAere is the need to examine the mean students‟ attitude scores. Table 4.12 presents the mean scRore of each of the groups‟ in students‟ attitude to practical chemistry. LI B DA N A Table 4.12: Estimated marginal means for Clas sI SBize for Post Students’ Attitude to Practical Chemistry Score OF Y 95%Confidence Interval TS I for Difference SIZE Mean R Std. Error Lower Bound Upper Bound LARGE I9V2.17 E0 .803 90.591 93.749 SMALL N 90.650 .653 89.366 91.933 EvaluateUd at covariates appeared in the model: PRE ATTITUDE SCORE = 86.7549 Table 4.12 shows that the mean score is higher for the students‟ in large class size (92.17) than those in small class size (90.65). Discussion 110 The result shows that students in large class size had greater mean score than the students in small class size this implies that problem-solving may be used for teaching large class size. In support of this result is the finding of Fleming, Toutant and Raptis (2002) who indicated that an increase in class size does not necessarily lead to a decrease in level of academic achievement. Likewise, a decrease in class size does not guarantee an improvement in the social environment of learning. They explained that the more important is what the teacher does with the opportunities provided by the size of the class. However in contrast to this result is Blatchford et al., (2003)‟s account of a survey of teachers‟ and head teachers‟ views which showed that practitioners believe that large class size affect teaching and learning and are particularly aware that larger clRasseYs could have an adverse effect on amount of teachers‟ attention. They found that smaller claAsses resulted in greater teacher knowledge of pupils, frequency of one to one contacts between tReachers and pupils, variety of activities, adaptation of teaching to individual pupils and opportuInBities to talk to parents. Other studies reported more individual teaching attention and more feLedback, while monitoring, checking understanding and offering appropriate feedback to indiviNdual children is more difficult in a large class, also learning of basic skills suffer in large classesA. Teachers of large classes are under stress and worn out spending many hours outside their cAontDact time marking. That the teacher child interactions are also concerned with management aBctivities and quelling rising noise levels. The behaviour of the pupils could be strained. This i s Iprobably related to the limited amount of space that the pupils had to move in. That groupingF pupils by ability are inevitably large and included a wide range of ability. The result of this sOtudy showed that the teachers made use of the problem- solving activities which eventually leYd t o an increase in mean gain of the large class size. There is no significant difference betweeIn Tthe two class sizes. S 4.1.3 Ho3b: There is noR significant main effect of class size on students’ achievement in practicEal chemistry Testing tIhVe significance of the main effect of class size (Large and Small) on students‟ achievemenNt in chemistry a 3 x 2 x 2 factorial ANCOVA test was run. Table 4.4 shows the ComposUite table for the ANCOVA Tests. From Table 4.4 it is clear that class size had significant effect on students‟ achievement in 2 chemistry, F(1,346) = 14.54, p < 0.05, partial η = 0.04. The effect size (4.0%) of class size on achievement in chemistry test was moderate. This result shows that the null hypothesis was rejected and the alternative hypothesis upheld. 111 Discussion This result shows that class size had significant effect on students‟ achievement in practical chemistry. It agrees with the reports of a study conducted in the United States by Averest and Mclennan (2011) which indicated a positive and significant effect of class size on children‟s test scores. They also reported a positive relationship between class size and test scores for Israel, but in contrast to this result they reported a negative but statistically insignificant effect of class size on test scores for Britain. Hanushek (2003) reported that class size is not significant in explaining students‟ performance. Averest and Mclennan (2011) further reported that time series evidence suggested that class size reductions in the United states over the last three decades havRe noYt led to improvements in students‟ performance. In Nigeria Babatunde and Olanrewaju (201A4) reported that class size has effect on students‟ achievement. On the contrary Adeyemi (200R8) discovered that there is no significant relationship among class size and students‟ learning oIuBtcomes. Having established that there was significant effect of class size o nL achievement in chemistry, there is the need to examine which group produced the higher meNan score in achievement. Table 4.13 presents the mean of each of the groups‟ scores in chemistrAy test items. D A IB OF Y Table 4.13: Estimated marginaIlT means for Class Size for Post Achievement in Chemistry ScoSre R V E 95%Confidence Interval N I for Difference SIZE U Mean Std. Error Lower Bound Upper Bound LARGE 16.377 .701 14.998 17.756 SMALL 19.432 .586 18.279 20.585 Evaluated at covariates appeared in the model PRE CHEMISTRY SCORE = 19.7103. 112 Table 4.14a: Pairwise Comparisons Post Hoc Test on Class Size in post Achievement in Chemistry Score. 95%Confidence Interval for Difference (I)SIZE (J)SIZE Mean Std. Error Sig Lower Upper Difference Bound BounYd R LARGE SMALL -3.055 .801 .000 -4.631 A -1.479 SMALL LARGE 3.055 .801 .000 1.479I B R 4.631 Mean difference is significant at p< .05 L N Table 4.14b: Pairwise Comparisons Post Hoc Test on Class ASize in post Achievement in Chemistry Score Level of Significance D A L I B S L O F * S * Y *= Significance difference SI T Table 4.13, 4.14a aEnd R4.14b show that students in small class size had higher mean score (19.43) in chemistry acIhVievement than students in large class size of mean score (16.38). Also these students in sNmall class size had higher mean difference of 3.05. Both are significant. U Discussion The results of this study show that students in small class size gained more academically than the students in the large class size with a greater mean difference of 3.06 in the achievement test. While the difference in mean between the large class size and small class size was only 1.52 in the students‟ attitude to practical chemistry score. This may be considered as one of the advantages of 113 small class size over the large class size. This result is in agreement with Blatchford et al., (2003)‟s report, who pointed out that small classes can encourage aspects of teaching that are the same as those identified in research on effective teaching (e.g immediate feedback, sustaining purposeful interactions) linked with the promotion of pupils achievement. Also in support of this is Kokkelenberg et al., (2005)‟s argument that courses geared towards promoting critical thinking and advanced problem-solving are best taught in a smaller classroom environment. Averest and Mclennan (2011) concluded that Senior Secondary Students in small sized classes show higher achievement in chemistry relative to their colleagues in large sized classes. Ogundipe (2004) showed that reduced class size with a 1:15 teacher- student ratio showed positive resultsR on Yreading and mathematics. Also Adeyemi (2008) found that schools having an average cAlass size < 35 obtained better results than those having > 35. R In contrast to the result of this study, are the results of some IstBudies which show no significant relationship between class size and students‟ performanc eL (Carpenter, 2006). While other studies in support of this study favour small class environmNents, results vary based on the criteria used to gauge student performance as well as the class sAize measure itself. When traditional achievement tests are used, small classes may provide no aDdvantage over large classes. However if additional performance criteria are used (e.g. long terBm rAetention, problem-solving skills), it appears that small classes hold an advantage (Aria and Wa lIker, 2004). F 4.1.4 Ho4a: There is no significant inte rOaction effect of treatments and level of possession of chemistry process skillYs on students’ attitude to practical chemistry score In order to test the signifIicTance of the interaction effect of treatments and level of possession of chemistry process skills oSn students‟ attitude a 3 x 2 x 2 factorial ANCOVA test was run. Table 4.1 shows the CompositeR table for the ANCOVA Tests. From TabVle E4.1 it is clear that interaction of treatments and chemistry process skills had 2significant effecIt on students‟ attitude, F(2, 346) = 3.31, p < 0.05, partial η = 0.019. The effect size of the interactiNon was fair (1.9%). This shows that the null hypothesis is rejected and the alternative hypotheUsis upheld. Discussion This result shows that the interaction between treatments and chemistry process skills had significant effect on students‟ attitude to practical chemistry. Research has demonstrated that attitude toward science changes with exposure to science but that the direction of change may be 114 related to the quality of that exposure, the learning environment and teaching method (Cracker, 2006). This shows that the exposure and the teaching method are of high quality to have a positive effect on students‟ attitude to practical chemistry. Cardelini (2006) discovered that students‟ attitude towards science is more likely to influence the success in science courses than success influencing attitude. Table 4.15 shows the mean, standard error and 95% confidence interval of the mean scores. The table shows that students in Experiment 2 with low skill had the highest mean score (93.99) in students‟ attitude. RY Table 4.15: Estimated marginal means for Treatments and Chemistry Process SAkills for Post Students’ Attitude to Practical Chemistry Score R IB L95% Confidence Interval A N for Difference Treatment Skill Mean StAd. EDrror Lower Bound Upper Bound IB EXP 1 HIGH 89.026 F 1.057 86.947 91.105 LOW Y 93 .7 O67 1.193 91.421 96.112 EXP 2 HIGH I T 92.053 1.661 88.786 95.319 LOWR S 93.994 1.146 91.740 96.247 CONTROL HEIGH 90.447 1.446 87.603 93.290 N I V LOW 89.174 .930 87.345 91.003 EvaluateUd at covariates appeared in the model: PRE ATTITUDE SCORE = 86.75 This result is in agreement with the findings of Senoocak, Taskesenligil and Sozbilir (2007) that there was a statistically significant difference between the problem-based learning and conventional groups in terms of their attitude towards chemistry, skills development and conceptual understanding. It is at variance with Frazer and Sleet cited in Sule (2000), findings that seventy six 115 percent of the unsuccessful students in a study they conducted had negative attitude towards problem-solving. To disentangle the interaction a graph is plotted. This is shown in Figure 4.1 Y RA R LI B AN Figure 4.1: Interaction of Treatments and Chemistry PrDocess Skills on Students’ Attitude to Practical Chemistry Score IB A This result of the study shows the efficacy oFf th e problem-solving strategy which has led to the development of high attitude in the stude nOts with low chemistry process skills. This was reversed in the control which is the conventioYnal group. There is interaction between the treatment and chemistry process skills on studeInTts‟ attitude to chemistry score. S 4.1.4 Ho4b: There is noR significant interaction effect of treatments and chemistry process skills oEn students’ achievement in practical chemistry A 3 x 2 x 2I Vfactorial ANCOVA test was run in order to test the significance of the interaction effect of treaNtment and skill on students‟ achievement in chemistry. Table 4.4 shows the Composite table forU the ANCOVA Tests. From Table 4.4 it is clear that interaction of treatments and chemistry process skills had 2 significant effect on chemistry achievement, F(2,346) = 5.11, p < 0.05, partial η = 0.029. The effect size of the interaction was moderate (2.9%). This result showed that the null hypothesis was not accepted. Discussion 116 The result of this study shows that the interaction of treatments and chemistry process skills had significant effect on students‟ achievement in practical chemistry. This finding is similar to that of several studies, such as Gonen and Basaran (2008), Ajzen and Fishbein (2000); Wilson, Ackerman and Malave (2000) who reported that students‟ positive attitude towards science correlate highly with their achievement in science. The results of this study show that the interaction of treatments and chemistry process skills is very strong because it had effect on both students‟ attitude and achievement in practical chemistry. These results also show that acquisition of chemistry process skills is important. Table 4.16 shows the descriptive statistics the mean, standard error and 95% RconYfidence interval of the mean scores. The table shows that students in Experiment 2 and withA High skill had the highest mean score (28.58) in chemistry achievement test. R Table 4.16: Estimated marginal means for Treatments and Chemistry PIrBocess Skills for Post Achievement in Chemistry Score L N 95A% Confidence Interval A D for Difference Treatment Skill Mean Std .I EBrror Lower Bound Upper Bound O F EXP 1 HIGH 25.3Y96 1.109 23.215 27.557 LOW S I T21.812 1.141 19.569 24.055 EXP 2 HIGRH 28.581 2.106 24.439 32.723 I V L EOW 21.457 1.111 19.273 23.642 CONTROL N HIGH 25.144 1.923 21.362 28.927 U LOW 15.037 1.059 12.954 17.119 Evaluated at covariates appeared in the model PRE CHEMISTRY SCORE = 19.7103 To disentangle the interaction a graph is plotted. This is shown in Figure 4.2 117 AR Y R Figure 4.2: Interaction of Treatments and Skill on Chemistry AchievemIeBnt Test Discussion L The possession of high skill and high scores in the chemAistrNy achievement test which is the result of this study is supported by Gok and Silay (2010) tDhat problem-solving is one of the most important issues in teaching and learning. The role of pAroblem-solving in science is indispensable. It is an integral part of science. Science itself isI aB problem-solving subject. It is a subject that revolves around finding one solution or the oth er to some problems. Problem-solving can and should be the centre of the instruction, also thFe way it is practiced must change, it should be a part of an active learning of the instructYiona l Oprocess. When students know all the relevant facts and principles necessary for the solutiTon of a problem, they may be unable to solve it because they lack any systematic strategy for gSuidIing them to apply such facts and principles. The result showed that Experiment 2 involved thRe students most in the problem-solving activities. 4.1.5 Ho5a: TheIreV is Eno significant interaction effect of treatments and class size on students’ Nattitude to practical chemistry InU order to test the significance of the interaction effect of treatments and class size on students‟ attitude a 3 x 2 x 2 factorial ANCOVA test was run. Table 4.1 shows the Composite table for the ANCOVA Tests. From Table 4.1 it is clear that interaction of treatments and class size had no significant effect 2 on students‟ attitude, F(2, 346) = 0.83, p > 0.05, partial η = 0.009. The effect size of the interaction was small (0.9%). This means that the null hypothesis was not rejected. 118 Discussion This result shows that the interaction between the treatments and large or small class size class size had no significant effect on students‟ attitude to practical chemistry. This shows that the interaction effect is very low. Table 4.17 shows the descriptive statistics, the mean, standard error and 95% confidence interval of the mean scores. The table shows that students in Experiment 2 and in large class size had the highest mean score in students‟ attitude to practical chemistry. RY Discussion A This result shows that Experiment 2 exposed students to more problem-soRlving activities and the teachers made the most use of the activities which led to the increase inI Battitude of the students in the large class size. L Table 4.17: Estimated marginal means for Treatments and ClasNs Size for Post Students’ Attitude to Practical Chemistry Score A D B A 95% Confidence Interval F I for Difference Treatment Class Mean O Std. Error Lower Bound Upper Bound Size T Y EXP 1 LARGE S I 91.925 1.231 89.503 94.347 SMEALRL 90.868 1.030 88.841 92.894 EXP 2 I V LARGE 93.591 1.644 90.358 96.824 U N SMALL 92.455 1.165 90.163 94.747 CONTROL LARGE 90.994 1.241 88.553 93.436 SMALL 88.626 1.190 86.285 90.967 Evaluated at covariates appeared in the model: PRE ATTITUDE SCORE = 86.7549 119 4.1.5 Ho5b: There is no significant interaction effect of treatments and class size on students’ achievement in practical chemistry Testing the significance of the interaction effect of treatment and class size on students‟ achievement in chemistry a 3 x 2 x 2 factorial ANCOVA test was run. Table 4.4 shows the Composite table for the ANCOVA Tests. From Table 4.4 it is clear that the interaction of treatments and class size had no significant 2 effect on chemistry achievement, F(2, 346) = 1.05, p > 0.05, partial η = 0.006. The effect size of the interaction was small (0.6%). The result showed that the null hypothesis is upheld. RY Discussion A The interaction of treatments and class size had no significant effect oRn achievement in practical chemistry. This shows that the effect of the interaction between tIreBatments and class size was so small that it had no effect on achievement in practical chemistr yL. In support of this result is Afolabi (2002), who found no significant relationship among clNass size and students‟ learning outcome in the treatment groups. A D Table 4.18 shows the descriptive statistics thBe mAean, standard error and 95% confidence interval of the mean scores. The table shows tha t Istudents in Experiment 2 in small class size had the highest mean score in chemistry achievemeFnt test. O Table 4.18: Estimated marginal meYans for Treatments and Class Size for Post Achievement in CheImTistry Score S R 95% Confidence Interval I V E for Difference Treatment N Class Mean Std. Error Lower Bound Upper Bound U Size 120 EXP 1 LARGE 16.515 .952 14.643 18.388 SMALL 20.692 .793 19.133 22.252 EXP 2 LARGE 19.342 1.385 16.617 22.067 SMALL 20.697 1.019 18.692 22.701 CONTROL LARGE 13.274 1.040 11.228 15.321 SMALL 16.907 1.004 14.932 18.881 Y Evaluated at covariates appeared in the model PRE CHEMISTRY SCORE = 19.7103A R R Discussion IB The result of this study on the effect of the interaction of treatmen tLs and class size shows that students in small class sizes in Experiments 1 and 2 had the high Nmean scores in the achievement test. This is supported by Mokobia and Okoye (2011)‟s anAd Falls (2003)‟s observations that, according to many parents, educators and policy makers,D smaller classes are an apparently full proof prescription for improving students‟ performanAce. That is fewer students means more individual attention from the teachers, calmer clas sIroBoms and consequently, higher test scores. F 4.1.6 Ho6a: There is no statistically sign iOficant interaction effect of chemistry process skills and class size on students’ Yattitude to practical chemistry The significance of thIe Tinteraction effect of chemistry process skills and class size on students‟ attitude was testedS a 3 x 2 x 2 factorial ANCOVA test was run. Table 4.1 shows the Composite table for the ARNCOVA Tests. From Table 4E.1 it is clear that the interaction of chemistry process skills and class size had 2 no significant efIfeVct on students‟ attitude, F(1, 346) = 0.90, p > 0.05, partial η = 0.003. The effect size of the interaNction was low (0.3%). The result shows that the null hypothesis is not rejected. U Discussion The result of this study shows that the interaction effect of chemistry process skills and class size was low and had no significant effect on students‟ attitude. Table 4.1 also shows that both 121 chemistry process skills and class size had no significant effect on students‟ attitude when considered separately. Table 4.19 shows the descriptive statistics the mean, standard error and 95% confidence interval of the mean scores. The table shows that students in large classes with low chemistry process skill had the highest mean score in students‟ attitude to practical chemistry. Table 4.19: Estimated marginal means for Chemistry Process Skills and Class Size for Post Students’ Attitude to Practical Chemistry Score Y AR 95%Confidence IntervRal for Diffe rLencIe B SKILL SIZE Mean Std Error Lower Bound NUpper Bound HIGH LARGE 90.780 1.239 88.343 D A 93.217 SMALL 90.237 1.065 88B.14A2 92.331 LOW LARGE 93.560 1.017 F 9I1.559 95.561 SMALL 91.062 .75 6O 89.575 92.550 Evaluated at covariates appeared iTn thYe model: PRE ATTITUDE SCORE = 86.7549 I Discussion S Although the result oRf this study shows that the interaction effect of chemistry process skills and class size had nIo Vsign Eificant effect on students‟ attitude, but students in large class size despite the size of the cNlass and their low level of chemistry process skills still had the highest mean score in studentsU‟ attitude to practical chemistry showed the effectiveness of problem-solving strategy. 4.1.6 Ho6b: There is no significant interaction effect of chemistry process skills and class size on students’ achievement in practical chemistry In order to test the significance of the interaction effect of chemistry process skills and class size on students‟ achievement in chemistry a 3 x 2 x 2 factorial ANCOVA test was run. Table 4.4 shows the Composite table for the ANCOVA Tests. 122 From Table 4.4 it is clear that the interaction of chemistry process skills and class size had 2 no significant effect on achievement in chemistry, F(1, 346) = 2.16, p > 0.05, partial η = 0.006. The effect size of the interaction was low (0.6%). The null hypothesis is not rejected. Discussion From the result of this study the effect of the interaction of chemistry process skills and class size was also low that it had no significant effect on achievement in practical chemistry, where as the effect of chemistry process skills and class size separately had significant effect on achievement in chemistry. AR Y Table 4.20 shows the descriptive statistics the mean, standard error anRd 95% confidence interval of the mean scores. The table shows that students in small class IsiBze with high skill had 23.489, which is the highest mean score in achievement in chemistry testL. N Table 4.20: Estimated marginal means for Chemistry ProcesAs Skills and Class Size for Achievement in Chemistry Score D B A 95%Confidence Interval F I for Difference SKILL SIZE Mean Std EOrror Lower Bound Upper Bound HIGH LARGE 19.258T Y 1.652 16.008 22.509 SMALL 2S3.4I89 1.541 20.458 26.520 LOW LARGEE R 13.496 1.052 11.426 15.566 SMIVALL 15.375 .917 13.570 17.179 EvaluateUd atN covariates appeared in the model: PRE CHEMISTRY SCORE = 19.7103 Discussion The result of this study shows that the students in small class size with high skill had the highest mean score in achievement in chemistry, where as they had the lowest score in attitude to chemistry scores. In support of this finding is the report of Aria and Walker, (2004) on studies in favour of small class environments. That the results vary based on the criteria used to gauge 123 students‟ performance as well as the class size measure, when traditional achievement tests are used, small classes may provide no advantage over large classes. However if additional performance criteria are used (e.g. long term retention, problem-solving skills), it appears that small classes hold an advantage. 4.1.7 Ho7a: There is no statistically significant interaction effect of treatments, chemistry process skills and class size on students’ attitude to practical chemistry. The significance of the interaction effect of treatments, chemistry process skills and class size on students‟ attitude was tested a 3 x 2 x 2 factorial ANCOVA test was run. TableR 4.1Y shows the Composite table for the ANCOVA Tests. A From Table 4.1 it is clear that interaction of treatments, chemistry procRess skills and class 2 size had no significant effect on students‟ attitude, F(2, 346) = 0.77, p > 0.05I, Bpartial η = 0.004. The effect size of the interaction was small (0.4%). The null hypothesis was Lnot rejected. N Discussion A The interaction is not significant. Therefore the AassDumption of homogeneity of regression slopes is not violated. This means full ANCOVA cBan be conducted. It follows that the effect of treatments on students‟ attitude to practical chem iIstry is not sensitive to chemistry process skills- class size combination. F Table 4.21 shows that students in Expe riOment 2 with low skill in large class size had the highest mean score of 95.01. This shows the Yeffectiveness of Experiment 2 approach. IT S VE R UN I 124 Table 4.21: Estimated Marginal Means for Treatment, Chemistry Process Skills and Class Size for Post Students’ Attitude to Practical Chemistry Score 95% Confidence IntervaRl Y for DiffeRrenAce Treatment Skill Class Mean Std. Lower I B Upper Size Error N Bou n Ld Bound EXP 1 HIGH LARGE 89.480 1.542 A 86.947 92.512 SMALL 88.572 1.4A63 D 85.694 91.450 LOW LARGE 94.370 I B 1.912 90.608 98.131 SMALL 9O3.16F4 1.436 90.340 95.984 EXP 2 HIGH LARGE Y 91.169 2.642 85.973 96.365 SMAILTS L 92.936 2.010 88.982 96.890 LOW R LARGE 95.013 1.960 92.158 99.869 I V E SMALL 91.974 1.183 89.648 94.300 CONTROL N HIGH LARGE 91.692 2.074 87.613 95.770 U SMALL 89.202 2.010 85.249 93.155 LOW LARGE 90.297 1.354 87.635 92.960 SMALL 88.050 1.278 85.536 90.564 Evaluated at covariates appeared in the model: PRE ATTITUDE SCORE = 86.7549 125 4.1.7 Ho7b: There is no significant interaction effect of treatments, chemistry process skills and class size on students’ achievement in practical chemistry A 3 x 2 x 2 factorial ANCOVA test was run in order to test the significance of the interaction effect of treatments, chemistry process skills and class size on students‟ achievement in chemistry. Table 4.4 shows the Composite table for the ANCOVA Tests. From Table 4.4 it is clear that interaction of treatments, chemistry process skills and class size 2 had no significant effect on students‟ achievement in chemistry, F(2, 346) = 0.35, p > 0.05, partial η = 0.002. The effect size of the interaction was very small (0.2%). Based on this the nullR hypYothesis was upheld. RA Discussion IB The result shows that the students‟ achievement in chemistry is nLot significantly affected by interaction of treatments, chemistry process skills and class size. NIt also shows that the effect of treatments on students‟ achievement in chemistry is not sensitiAve to chemistry process skills-class size combination. This result when viewed against the bAackDground of main effect of treatments on students‟ attitude to and achievement in practical chemistry tends to suggest that practicing chemistry teachers should use problem-solving s trIatBegy for teaching, irrespective of the chemistry process skills-class size combination. AlthoFugh treatments significantly improved the level of students‟ achievement in chemistry highlOy, so also chemistry process skills and class size but the levels of this increase were not highY. Th is should be expected because studying science especially chemistry using problem-solvingI Tstrategy is not common in our schools. S Table 4.22: Estimated mRarginal means for Chemistry Process Skills and Class Size for AchVieveEment in Chemistry Score I N 95% Confidence Interval U for Difference Treatment Skill Class Mean Std. Lower Upper Size Error Bound Bound 126 EXP 1 HIGH LARGE 17.581 1.396 14.934 20.328 SMALL 23.211 1.363 20.531 25.891 LOW LARGE 15.449 1.620 12.264 18.635 SMALL 18.174 1.302 15.613 20.735 EXP 2 HIGH LARGE 21.989 2.679 16.721 27.258 SMALL 25.173 2.243 20.761 29.585 Y LOW LARGE 16.694 1.658 13.434 19.95A4 R SMALL 16.221 1.141 13.976 B 1R8.466 CONTROL HIGH LARGE 18.205 2.260 13.7 6L0 I 22.650 SMALL 22.084 2.192 A N 17.774 26.394 LOW LARGE 8.344 1.31D3 5.762 10.926 SMALL 11.729 I B A1.251 9.268 14.190 Evaluated at covariates appeared in the model:F PR E ATTITUDE SCORE = 19.7103 O From table 4.22 students in Exp eriment 2 with high skill and in small class size had the highest mean score in the achieIvTemYent in chemistry test. This further shows the effectiveness of Experiment 2 approach. S R Table 4.23: BetweenE-Subject Factor V NI Value Label N TREATUMENT 1.00 EXP 1 128 2.00 EXP 2 105 3.00 CONTROL 126 SKILL 1 HIGH 136 127 2 LOW 223 SIZE 1 LARGE 219 2 SMALL 140 Table 4.23 shows the number of subjects in each of the groups. Discussion Y From this table the total number of students in the large class size is 219 whAereRas in Table 3.3 the total number of students in the large class size was 299. The difference in the number of students shows the disadvantage of large class size, where these students did Ronly the pretest or posttest and not both as expected. This is the reason why the number of stuIdBents in Table 3.3 (439) is greater than the number of students in the analysis (359) as in TLables 4.1 and 4.4. This is supported by Wang and Zhang (2011) who wrote that large clasAses Nare difficult to control. AD IB O F SI TY VE R I N U CHAPTER FIVE 5.0 SUMMARY OF FINDINGS, IMPLICATIONS AND RECOMENDATIONS 128 This chapter presents a summary of the findings discussed in chapter four, their educational implications and proffers some recommendations. It also presents some limitations of the study and suggestions for further research. 5.1 Summary of Findings 1 The treatments had no effect on students‟ attitude to practical chemistry, but had effect on achievement in chemistry. This implies that students‟ attitude may not have effect on achievement in chemistry. 2 Chemistry process skills also did not affect the students‟ attitude to practical cheRmisYtry, but affected the achievement in chemistry. A 3 Class size also had no effect on students‟ attitude to practical chemistryR, but had effect on achievement in chemistry. This may be that at the Senior SecoInBdary School level the students already formed their attitude to practical chemis trLy such that none of the treatments, chemistry process skills or class size had effect oNn it. 4 The two way interaction of treatments and chemistry Aprocess skills had effect on both students‟ attitude to practical chemistry and aAchieDvement in chemistry. This shows the importance of acquisition of chemistry process skills. 5 On the contrary the two way interaction oIf Btreatments and class size did not affect both students‟ attitude to practical chemistryF and achievement in chemistry. 6 The two way interaction of class siOze and chemistry process skills had no effect on both the students‟ attitude to practical Yche mistry and achievement in chemistry. 7 The three way interactionI oTf treatments, class size and chemistry process skills had no effect on both students‟ attiStude to practical chemistry and achievement in chemistry. 8 Students exposed Rto Experiment 2 had the highest mean score in students‟ attitude to and achievemeVnt iEn chemistry. 9 Students Iwith low chemistry process skills had higher mean score in students‟ attitude to practNical chemistry, but students with high chemistry process skills had higher mean score iUn achievement in chemistry. 10 Students in large class size had the higher mean score in students‟ attitude to practical chemistry, while students in small class size had the higher mean score in achievement in chemistry. 11 Students exposed to Experiment 2 with low chemistry process skills had the highest mean score in the two way interaction between treatments and chemistry process skills in 129 students‟ attitude to practical chemistry. The students in Experiment 2 group with high chemistry process skills had the highest mean score in the two way interaction between treatments and chemistry process skills in achievement in chemistry. 12 Also students in Experiment 2 group in large class size had the highest mean score in the two way interaction between treatments and class size in students‟ attitude to practical chemistry. Again those in this group but in small class size had the highest mean score in achievement in practical chemistry in the two way interaction. 13 Students in large class size with low chemistry process skills had the highest mean Yscore in the two way interaction between class size and chemistry process skills in studeRnts‟ attitude to practical chemistry. While students in small class size with high chemistrAy process skills had the highest mean score in the two way interaction between class Rsize and chemistry process skills in achievement in chemistry. IB 14 The three way interaction of treatments, chemistry process skills aLnd class size had no effect on both students‟ attitude to and achievement in chemistry.N Students in Experiment 2 group with low skill in large class size had the highest mean scAore in students‟ attitude to practical chemistry, while students in this group with highA skiDll and in small class size had the highest mean score in achievement in chemistry. However there was no effect of treatments, c hIeBmistry process skills and class size on students‟ attitude to chemistry. Also the two way inteFraction of treatments and class size, class size and chemistry process skills and the three wOay interaction of treatments, class size and chemistry process skills had no effect on stYudents‟ attitude to practical chemistry. Only the two way interaction of treatments, and chIemTistry process skills had significant effect on the students‟ attitude to practical chemistry. S On the contrary Rthe treatments, chemistry process skills and class size had significant effect on students‟ achiVevemEent in chemistry. Also the two way interaction of treatments and chemistry process skills hIad significant effect on students‟ achievement in chemistry too, but the two way interaction oNf treatments and class size, class size and chemistry process skills and the three way interactiUon of treatments, class size and chemistry process skills had no significant effect on students‟ achievement in chemistry too. In establishing which group had the highest mean score, it was discovered that students‟ exposed to Experiment 2 had the highest mean score in the following: 1 Attitude to practical chemistry. 2 Achievement in chemistry. 130 3 The two way interaction between treatments and chemistry process skills on students‟ attitude to practical chemistry, students‟ with low chemistry process skills had the highest. While students‟ with high chemistry process skills had the highest mean score in achievement in chemistry. 4 The two way interaction between treatments and class size, students in the large class size had the highest mean score in students‟ attitude to practical chemistry. Also students in small class size had the highest mean score in achievement in chemistry. Students with low skill had higher mean gain in students‟ attitude to practical chemistry while students with high skill had the highest mean score in achievement in chemistry. Students inR larYge class size had higher mean gain in students‟ attitude to practical chemistry, whAile students in small class size had the higher mean gain in achievement in chemistrRy. In the two way interaction between class size and chemistry process skills, studentsI Bin large class size with low chemistry process skills had the higher mean score in st uLdents‟ attitude to practical chemistry. While students in small class size with high cNhemistry process skills had the highest mean score in achievement. A From the results, the treatments, chemistry process sAkillDs and class size had significant effect on the students‟ achievement in chemistry. Also, students exposed to Experiment 2 had the highest mean score in all the variables which shows the eIffBectiveness of the method, while students with high skill and those in small class size had the Fhigher mean score in achievement test. O 5.2 Implications and RecommendYati ons The study revealedI tThe degree of influence of problem-solving, level of acquisition of chemistry process skills anSd effect of class size on attitude to and achievement in practical chemistry in Oyo staRte. These findings have implications for education policy makers, administrators, cuVrricEulum planners or developers and practicing teachers. The result of this study has shown that pIroblem-solving strategy in the teaching and learning of chemistry is better than the conventionaNl (control) method. Problem-solving strategy has also been found to be more effective in improUving the problem-solving attitude and academic performance of the students, not only in the small classes but in the large classes, and students with low chemistry process skills. It has also been found that the problem-solving approach in Experiment 2 is more effective than the problem- solving approach in Experiment1 in improving the attitude and academic performance of the students in the large class and those with low chemistry process skills. 131 Practicing Teachers: In the light of these findings, it is necessary for chemistry teachers to review their methods of teaching to be student centered but guided by the teacher especially in large classes as we have in most of our schools, using problem-solving strategy. The inability of science teachers to use problem-solving strategy may be due to lack of understanding of the problem- solving instructional approaches and the implementation, or due to conservatism, where in teachers tend to teach the way they were taught. Teacher education should help teachers to be flexible enough to easily adapt to changes, since science is dynamic. There is need for pre- service and in- service courses, workshops and seminars that focus more on the role of practical work, especially problem-solving strategy, in creating oRpporYtunities for students to learn and do science. Students should be guided to discover Ascientific facts themselves. There is therefore need for teachers to motivate, encourage andR help students to develop positive attitude towards chemistry, which can be achievedI Bthrough the teaching methodology (problem- solving strategy) L Teachers should attend in- service training, workshops and Nseminars to be able to improve their methodologies and update their knowledge on the couArse contents. This would help the science teachers to learn more about problem-solving tAeacDhing strategy, knowledge and skills for laboratory work, which they can impact on the students. IB Curriculum Planners: There is need to Fchange science teachers‟ education courses, so that more problem-solving approaches could Obe incorporated. There is need to revise the chemistry curriculum to give room for practicaYl or iented topics and activities that will enhance technological development of the nation. This IwTill help to develop scientific potentials of our youths. S Policy Makers and AdRministrators: There is theV neEed to reinforce the monitoring units to ensure that teachers use the right methodology anId carry out practical frequently. Effective and workable facilities should be provided if Nteachers are to venture into a more tasking problem-solving instructional approach. LaboratoUry environment should be conducive and motivating to both teachers and students. Science teachers need incentives as par fantastic science teachers‟ allowance to enable them cope with the demanding nature of problem-solving. Laboratory assistants should be posted to schools to make the setting of the laboratory for practical easier and faster for the teachers. Also four periods should be allotted to science subjects and these should be double periods each, so that the teachers will have enough time to perform experiments and practical during the lesson where necessary. 132 5.3 Limitations and Suggestions for Further Research This study was limited to SS 2 science students in three educational zones and nine local government areas in Ibadan and Oyo towns. Further research in the other educational zones and local government areas is recommended to provide more room for generalization. The study focused on public state schools, further research could focus on private and federal government schools. The content areas for this study are: Nature of Matter, Separating Techniques and Volumetric Analysis. The problem-solving instructional guides were developed in thRese Ycontent areas. There is therefore the need to develop more problem-solving instructional Aguides in other content areas such as Atomic Structure, Gas Laws, Metals and Non metals and ORrganic chemistry. Outstanding limitations to this study are inadequate chemistry aIppBaratus and laboratory assistants. Most schools visited had limited number of chemistry ap pLaratus compared with the number of students offering the subject in each school, the reseaNrcher carried some apparatus to some of the schools used for the research despite the fact thatA these schools were selected on the basis of the availability of these apparatuses. In mostA of Dthe schools the number of periods for chemistry has been reduced to three periods because of the increase in the number of subjects offered by the students, this is not adequate espec iaIllBy the single is too short for the teachers and the students to perform experiments or practical. FNo laboratory assistant in all the schools used for the research. 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AN BA D F I O T APYPENDIX IA LABORATORY PROBLESM-ISOLVING MODEL (LAPSOM) INSTRUCTIONAL GUIDE on Nature of Matter R The teacher teacIhVes t Ehe students the background information first. The teacNher asks the following questions: What is matter? What is Uit made up of? He explains that matter is anything that has weight and occupies space. It is made up of discrete particle, such as atoms and molecules. An atom is the smallest particle of an element which can take part in chemical reaction. The teacher asks the questions; What is a molecule? 152 What is a compound? The teacher explains that a molecule is the smallest particle of a substance that can normally exist alone and still retain chemical properties of that substance either an element or compound. Elements combine to form compounds while atoms combine to form molecules. The teacher asks the following question; What are physical and chemical changes? The teacher explains that a physical change is one which is easily reversed and in which no new substances are formed. Classify the following into physical and chemical changes. Salt + water salt solution RY Wood ash +gases A Stage 1- Recognize the problem. R The students are given the laboratory manual which consists of stIagBes 1 -5. The practical problem posed is; L Nature of matter – physical and chemical changes, elements, coNmpounds and mixtures and the determination of empirical formula of magnesium oxide. A Read carefully the laboratory manual. D Recognize the apparatus provided. A Check the soundness of the apparatus. IB Read the instruction again. F Sketch a diagram of how you intend to a rrOange the apparatus to enable you solve the problem. ITY Stage2: Recall backgroundS Information. Actions: (a) Write downR known general principles and mathematical expressions are necessary for solving the problem .E (b) List possibleI sVources of error in solving the problem. (c) RecognizNe independent and dependent variables in the problem and note their relationship. U STAGE 3; Conduct the Experiment, Predicting from data. METHOD OR PROCEDURE Students should Weigh the crucible with the lid. Clean magnesium ribbon with sandpaper. 153 Cut 15cm of clean magnesium ribbon into the crucible. Place the crucible on the tripod stand, heat strongly and remove the lid at intervals with the tong. When the magnesium has burned completely, remove the lid and continue heating for two minutes. Remove the crucible from the tripod stand and keep in a desiccator. Weigh the crucible, content and lid when it is completely cold. Repeat heating for three minutes. Allow the crucible, content and lid to cool then weigh again. OBSERVATION: Students should record all observations. Repeat the experiment again and calculate the average of the figures. RESULT: RY Mass of crucible and lid= A Mass of crucible, lid and magnesium = R Mass of crucible, lid and content after heating = IB Mass of content = L Mass of magnesium = N Mass of oxygen = A QUESTIONS: D 1) Name the elements involved in the experiment? A 2) Name the compound formed? IB 3) What is the mass of crucible and lid? F 4) Why do we need to clean the magnOesium ribbon? 5) Why do we need to lift the lidY wh en the magnesium was burning? 6) Why do we need to contiInuTe to heat the crucible for another 2 minutes? 7) What makes the magnSesium change color? 8) What supports theR burning of magnesium? 9) What is theV namEe of the new substance? 10) How wouIld you find out the mass of magnesium and mass of the magnesium oxide 11) If the Nrelative atomic mass of magnesium is 24 and oxygen is 16, how many atoms of mUagnesium were used? 12) How many atoms of oxygen were used? 13) What is the ratio of atoms of magnesium to oxygen? 14) Derive the formula for the magnesium oxide? 15) Does the experiment involve physical or chemical change? Give reason for your answer? 154 16) What have you learnt from the experiment which is applicable to everyday life? 17) Is there any reason for repeating the experiment and why? NOTE: There are no variation of variables and plotting of graphs in this study. Part of stages 3B-5A are not necessary, stage 5B is taken care of by answering the questions. The answers to the questions will determine whether to repeat the experiment or not. RY RA IB L AN AD IB O F TY SI E R APPENDIX IB LABORATORIYV PROBLEM-SOLVING MODEL (LAPSOM) INSTRUCTIONAL GUIDE on SeparatiNon Techniques The teacUher teaches the students the background to the problem. Mixtures contain two or more different substances. Each constituent of a mixture still retains its individual properties. We can take advantage of these characteristics to separate mixtures. Thus the technique employed in separating mixtures makes use of the physical properties of their constituents. 155 SUBLIMATION: Asks the students to state the states of matter and sublimation. The three states of matter are solid, liquid and gas, while sublimation is the direct conversion of a solid to the gaseous state directly without changing to the liquid state. Asks the students to write examples on the board. Gives example of camphor. FILTRATION: This is used to separate an insoluble solid from a liquid. This involves the use of a filter paper which is porous in nature and allows the passage of only water which is the filtrate, while the particles remain in the funnel as residue. Industries such as water purification plant and breweries use filtration to remove solid particles from liquids. Also in the purification ofR pipYe-borne water, the water strains through the various layers of the filter bed, leaving all formAs of suspended materials behind. The filtered water is then treated with chemicals to kill any bRacteria in it before being piped to the consumers. LI B EVAPORATION TO DRYNESS: This method can be used toN recover a solid solute from a solution, the solvent escapes into the atmosphere as vapour leAaving the solute in the evaporating dish. AD Solution solute + solvent IB Evaporation can be done at a steady rate usingF a water bath or a sand bath. This method cannot be used to recover salts that are easily desOtroyed by heating. This method is used in salt making industries. Sea water is pumped intoY tre nches and allowed to evaporate under the heat of the sun along the Western Coast of AfricIaT. All the water dries up leaving behind the salt. RS SEPARATING FUNENEL METHOD: Some liquids do not mix together; these are known as immiscible liquIidVs e.g water and oil, water and petrol. Those that mix together to form a homogenousN liquid are called miscible liquids e.g water and alcohol. The immiscible liquids form two distUinct layers when added together, a separating funnel can be used to separate the two layers into two different containers, the lower denser layer is collected before the less dense upper layer. STAGE 1: Recognize the problem. The students are given the laboratory manual which consists of stages 1-5 of the model. a. The students should recognize that the problem posed is the aim of each experiment. b. Read carefully the laboratory manual. 156 c. Identify the apparatus provided. d. Check the soundness of the apparatus. e. Read the instruction again. f. Sketch the diagram of how you intend to arrange the apparatus to solve the problem. STAGE 2: Recall background information. (a) List the sources of error and precautions to be taken in each experiment. STAGE 3: Conduct the Experiment. Y SUBLIMATION: AR  Pour the mixture to be separated for example sodium chloride ( NaCl) anRd Iodine (I2) in an evaporating dish. IB  Cover with an inverted funnel and heat indirectly on a water bat hL.  Note what happens to the iodine. N  Scrape off the iodine into a Petri dish. A PRECAUTIONS: D  Avoid gas leakage during heating. IB A  Be very careful when removing the funFne l, so that the iodine does not mix with the sodium chloride. O QUESTIONS Y 1 Why do we heat indirectly on Ia Twater bath?. 2 Why do we cover with invSerted funnel? 3 What is the applicaEtionR of this method in everyday life? FILTRATION: IV  Put tNhe funnel on the conical flask.  FUold the filter paper in to four equal parts forming the shape of a funnel.  Open one end of the filter paper and put it inside the funnel.  Pour the mixture of the muddy dirty water iside the funnel.  What can you observe?  Note the colour of the water in the conical flask. QUESTIONS: 157 1 What is in the funnel? 2 Why is it that only the water molecules pass through the filter paper? 3 Give examples of filtration apparatus we use at home. 4 What is the application in everyday life? EVAPORATION  Fill the evaporating dish with the salt solution.  Place the water- bath on the tripod stand with the fire source. Y  Place the evaporating dish on the water bath R  Watch as the water evaporates leaving the salt in the evaporating dish. A QUESTIONS: R 1 What happens if the mixture is heated directly? IB 2 Explain what happens to the solvent? L 3 What is the application in everyday life? AN SEPARATING FUNNEL METHOD: D  Clamp the separating funnel on the retort staInBd. A  Close the tap and fill it with the mixture of water and oil.  What do you observe? F  The mixture separates into two di sOtinct layers.  Open the tap and allow theT waYter to drain into a beaker.  Close the tap and draSin thIe oil into another container. OUESTIONS: 1 Is there any differRence in the densities of the two liquids? 2 What happensE if the densities are equal? 3 WhaNt is Ith Ve application in everyday life? U APPENDIX 1C Laboratory Problem-Solving Model (LAPSOM) Instructional Guide on Quantitative Analysis The teacher teaches the student the background information. There are two beakers containing two unknown solutions. The students are asked to identify each solution using red and blue litmus papers. Acid turns blue litmus paper red while 158 Base turns red litmus paper blue. The students are asked to define an acid , The definition is written as – An acid is a substance which produces hydrogen ions (or protons ) as the only positive ion when dissolved in water. There are two classes of acids namely organic acids and mineral or inorganic acids. They are asked to give examples of these acids. Examples of organic acids are Ethanoic acid in vinegar, Lactic acid in milk, citric acid in lime, lemon, and vitamin C. While the inorganic acids are Hydrochloric acid from hydrogen and chlorine, tetraoxosulphate(VI) acid , trioxonitrate(V) acid . Strong acid ionize completely in water to give hydrogen ions which is positively charged or cations and negatively charged ions or anions Y + - e.g hydrochloric acid HCL H + CL . AR While weak acids are only partially ionized in water R - + e.g ethaonic acid HCOOH COO + H . LIB if a large quantity of water is added to a small quantity of acid, theN res ulting acid solution is dilute. If a little quantity of water is added to a relatively large quantityA of acid, the solution of the acid will be concentrated. The solution that turns blue litmus paper toD red is an acid. Bases and Alkalis: The term base was originaBlly Aused to describe substances that turned red litmus to blue and neutralized the propertFies oIf acids in aqueous solutions e.g oxides and hydroxides of metals Na2O, K2O, MgO. OMost metallic oxides are insoluble in water, while some dissolve in water to form hydroxide Y Na2O(s) + H2O(l) I T 2NaOH(aq) Sodium oxide S sodium hydroxide A soluble basic hydEroxRide is known as alkali. A strong alkalis ionize completely in aqueous -solutions to proIduVce negatively charged hydroxide ions, OH , and positively charged metallic ions e.g sodium Nand potassium hydroxides while weak alkali produce relatively few ions e.g calcium hydroxidUe. The two solutions in the beakers are poured into a bigger container and tested with litmus paper. The solution formed has no effect on litmus paper, which means it is neutral to litmus. This shows that when acid and alkali react together salt and water are formed, which is neutral to litmus paper and the reaction is known as Neutralization. Acid + Base Salt + water + - e.g HCL(aq) + NaOH(aq) Na CL (aq) + H2O(L). 159 Neutralization is a process in which an acid reacts completely with an appropriate amount of alkali (or any other base) to produce a salt and water only + Neutralization can also be defined as the combination of hydrogen ions, H and hydroxide ions OH, to form water molecules, H2O. A salt is formed at the same time. So a base can be defined as a substance which will neutralize an acid to yield a salt and water only. The acidity and alkalinity of substances are measured using a scale of numbers from 0 to 14 known as the pH scale. A solution with a pH value of 7 is neutral i.e neither acidic nor alkaline. A Ysolution with a pH value less than seven is acidic, while a value more than seven is alkaliRne. Acidity increases with decreasing pH, values while alkalinity increases with increasing pHR vaAlues. Acid- base indicators are dyes which change colour according to the pIHB of the medium, Each indicator has its own specific pH range over which it changes. TheL pH of a solution can be measured by using universal indicator and pH meter. N Indicator Methyl Orange Litmus DA Phenolphthalein pH range 3.1- 4.6 5.0- 8.A0 8.3- 10.00 Colour change Orange PIuBrple P a l e Pink Acid medium Red F Red Colourless Alkaline medium Yellow O Blue Pink Titration is the method emTploYyed in volumetric analysis. In this method, a solution which is the acid from a graduated vSesseIl is added to a known volume of a second solution, the base in a conical flask until the cRhemical reaction between the two is just completed. This is shown by a colour change of the Eindicator in the resulting solution. In any titration a standard solution which is one with a knowVn accurate concentration must be used to react with a solution of unknown concentratioNn. TIhe reacting volumes of the solutions are then used to calculate the unknown concentrUation of the solution. The concentration of a solution is the amount of solute in a given 3 3volume of the solution. It can be expressed as moldm or gdm . The concentration of a solution in 3 moldm is the molar concentration. A molar solution of a compound is one which contains one 3 mole or the molar mass of the compound in one dm of the solution. For example the molar mass of sodium hydroxide is 40g/mol, therefore a molar solution of sodium hydroxide contains 1 mole or 3 40g of the hydroxide in 1dm of the solution. 160 Formulae for the calculations involving volumetric analysis. Concentration of acid Ca X Volume of acid VA = Number of moles of acid na Concentration of base CB Volume of base VB Number of moles of base nb CAVA = na CB VB nb Number of moles of a substance = Number of particles = N ……………………………..(1) 23 6.02 x10 L Y 3 -3 Number of moles of a substance = Volume(cm ) x Concentration in moldm ………R..(2) 1000 RA Number of moles of a substance = Mass of substance in gm ………I…B………………(3) Molecular mass -3 -3 L Concentration in moldm = Concentration in gdm …N……………………..... (4) Molecular mass A Sources of error and Precaution. AD  Rinse the burette and pipette with the sIoBlution to be used in them to avoid diluting with the remains of water used in them.  Air bubbles must be removed OfromF the burette and pipette, to obtain accurate volume of solution.  Never rinse the titraItiTon Yflask or conical flask with the solution it is to hold, to avoid using more solution than required.  Do not blowR the Slast drop at the tip of the pipette to avoid using volume than the pipette is construEcted to deliver.  TheI bVurette tap must be tight to avoid leakage.  NRemove the funnel from the burette before titration commences to avoid an increase in Uvolume of the solution in the burette.  Clamp the burette in a vertical position to avoid error due to parallax while taking the burette reading.  Shake titration flask during titration to obtain a homogenous solution.  Place the titration flask on a white surface to avoid over-shooting the end- point. 161 STAGE 1: Recognize the problem. The students are given the laboratory manual which consists of stages 1-5 of the model. a The students should recognize that the problem posed is the aim of each experiment. b Read carefully the laboratory manual. c Identify the apparatus provided. d Check the soundness of the apparatus. e Read the instruction again. f Sketch the diagram of how you intend to arrange the apparatus to solve the prYoblem. STAGE 2: Recall background information. AR (b) List the sources of error and precautions to be taken in each experiment. R STAGE 3: Conduct the Experiment. LIB  Wash the conical flasks, burette, pipette and beakers N properly with soap solution and rinse with distilled water first, then with the soluAtion to be poured inside each one except the conical flask. D  Drain all the washed apparatus. A  Fill the burette with the acid to the z erIoB mark.  Pipette the base into the conicalF flasks and add one or two drops of indicator.(methyl orange). O  Record the initial volumYe of the acid.  Open the tap of theI bTurette and run the acid into the conical flask containing the base.  Shake the mixtSure to make a homogenous solution until there is a colour change.  Read thEe acRid level in the burette and record as final level of acid.  DedVuct the two readings and record as the volume of acid used.  NReIpeat the experiment three more times. 3U Titration Reading.Cm 1 2 3 3Final burette reading. (Cm ) A 3 Initial burette reading. (Cm ) B 3 Volume of Acid used. (Cm ) X = A-B. 3 Volume of Base solution = 25.00 / 20.00 cm 3 Mean volume of acid used = X cm a. Write the equation of the reaction. 162 b. Write your observations. QUESTIONS: 1. Why do we need to clean the pipette, burette, and conical flasks? 2. Why do we rinse the pipette and conical flask with the base and the burette with the acid? 3. What is the purpose of the indicator in the experiment? 4. What is the volume of acid used each time? 5. How would you obtain the number of moles taking part in the reaction? 6. What is the mole ratio of the acid or base? RY 7. 3Derive an expression for the concentration in mol/dm of the acid. A R LI B N AD A F I B O ITY S VE R I UN APPENDIX IIA 163 Hands-on and Minds-on Problem-Solving Model (HAMPSOM) Instructional Guide on Nature of Matter STAGE 1A: Problem Perception The teacher writes the aim of the experiment which is the problem. STAGE 1B: Acquiring related theory The teacher asks the following questions. What is matter? Y What is it made up of? R He allows them to answer the questions A He explains that matter is anything that has weight and occupies space. It is mRade up of discrete particles, such as atoms and molecules. An atom is the smallest particle oIf Ban element which can take part in chemical reaction. L The teacher asks the following questions: N What is a molecule? A What is a compound? AD He allows them to answer the questions B He then explains that a molecule is the smallest p arIticle of a substance that can normally exist alone and still retains the chemical properties of thaFt substance either an element or compound. Elements combine to form compounds while atom s OY combine to form molecules. The teacher asks the following questions: What is a physical change? IT What is a chemical changRes?S He allows the studentEs to answer. He explains thatI aV physical change is one which is easily reversed and in which no new substances are formed. N The teacUher asks them to classify the following into physical and chemical changes Salt + water salt solution Wood ash + gases 164 DIAGRAM STAGE 1C: Planning experiments Using the diagram the students should: (a) identify the apparatus for the experiment. (b)Label the apparatus in the diagram. Y (c) Check the soundness of these apparatus. R (d) Students should write the sources of error and the precautions to be taken. A Teacher assists the students IB R STAGE 2A: Recalling theory L Students should N (a) Write down the general principle and laws. A (b) Recall the sources of error. AD STAGE 2B: Performing Experiment or Practic aIl B Method or Procedure: Students should O F Weigh the crucible with the lid. Y Clean magnesium ribbon witIhT sandpaper. Cut 15cm of clean magneSsium ribbon into the crucible. Weigh the crucibEle wRith lid and Magnesium ribbon Place the crucVible on the tripod stand, heat strongly and remove the lid at intervals with the tong. I WheUn thNe magnesium has burned completely, remove the lid and continue heating for two minutes. Remove the crucible from the tripod stand and keep in a desiccator. Weigh the crucible, content and lid when it is completely cold. Repeat heating for three minutes. Allow the crucible, content and lid to cool then weigh again. 165 STAGE 3A: Observation: Students should record all observations. The teacher goes round to correct those who are not following the instructions. RESULT: Mass of crucible and lid= Mass of crucible, lid and magnesium = Mass of crucible, lid and content after heating = RY Mass of content = A Mass of magnesium = R Mass of oxygen = IB L QUESTIONS: N 1) Name the elements involved in the experiment? A 2) Name the compound formed? D 3) What is the mass of crucible and lid? A 4) Why do we need to clean the magnesium r ibIbBon? 5) Why do we need to lift the lid when theF magnesium was burning? 6) Why do we need to continue to he aOt the crucible for another 2 minutes? 7) What makes the magnesium cYhange color? 8) What supports the burningT of magnesium? 9) What is the name of tShe nIew substance? 10) How would you fRind out the mass of magnesium and mass of the magnesium oxide. 11) If the relatVive Eatomic mass of magnesium is 24 and oxygen is 16, how many atoms of MagnesiumI were used? 12) HowN many atoms of oxygen were used? 13) WUhat is the ratio of atoms of magnesium to oxygen? 14) Derive the formula for the magnesium oxide? 15) Does the experiment involve physical or chemical change? Give reason for your answer? 16) What have you learnt from the experiment which is applicable to everyday life? 17) Is there any reason for repeating the experiment and why? 166 Teacher assists the students APPENDIX IIB HANDS-ON AND MIND-ON PROBLEM-SOLVING MODEL (HAMPSOM) INSTRUCTIONAL GUIDE on Separation Techniques STAGE 1A: Problem Perception. The teacher writes the aim of the experiment which is the problem. Separation techYniques- sublimation, filtration, evaporation and separating funnel method. AR STAGE 1B: Acquiring Related Theory R The teacher asks the students to explain mixture. IB He allows them to answer. L He then explains to them that mixtures contain two or more diAfferNent substances. Each constituent of a mixture still retains its individual properties. We can taDke advantage of these characteristics to separate mixtures. Thus the technique employed in sepAarating mixtures makes use of the physical properties of their constituents. IB SUBLIMATION: The teacher asks the studenFts to state the three states of matter. He asks them to explain the change of sOtate from one form to another. He explains to them that sublimation is the direct conversiTon Yof a solid to the gaseous state directly without changing to the liquid state. Asks the studentSs toI write examples on the board. He gives example of camphor. Diagram ER IV N U FILTRATION: The teacher asks the students to explain filtration and give examples. After listening to their explanation of the students, he explains to them that filtration is used to separate an 167 insoluble solid from a liquid. This involves the use of a filter paper which is porous in nature and allows the passage of only water which is the filtrate, while the particles remain in the funnel as residue. Industries such as water purification plant and breweries use filtration to remove solid particles from liquids. Also in the purification of pipe-borne water, the water strains through the various layers of the filter bed, leaving all forms of suspended materials behind. The filtered water is then treated with chemicals to kill any bacteria in it before being piped to the consumers. Diagram: RY A BR N LI DA EVAPORATION TO DRYNESS: This method can bAe used to recover a solid solute from a solution, the solvent escapes into the atmospher e IaBs vapour leaving the solute in the evaporating dish. F Solution solute + solvenOt TY Diagram: SI R V E NI U Evaporation can be done at a steady rate using a water bath or a sand bath. This method cannot be used to recover salts that are easily destroyed by heating. This method is used in salt making industries. Sea water is pumped into trenches and allowed to evaporate under the heat of the sun along the western coast of Africa. All the water dries up leaving behind the salt. 168 SEPARATING FUNNEL METHOD: He explains to them that some liquids do not mix together these are known as immiscible liquids e.g water and oil, water and petrol. Those that mix together to form a homogenous liquid are called miscible liquids e.g water and alcohol. The immiscible form two distinct layers when added together, a separating funnel can be used to separate the two layers into two different containers, the lower denser layer is collected before the less dense upper layer. Diagram: AR Y R IB STAGE 1C: Planning Experiments. L (a) Using the diagrams the students should identify the apparatuNs for each experiment. (b) Label the diagrams. A (c) Check the soundness of these apparatuses D (d) Students should write the sources of error aAnd the precautions to be taken in each experiment. IB Teacher assists the students F STAGE 2A: Recalling Theory. O Students should Y (a) Write down the generSal pIr Tinciples and laws necessary for solving the problem. (b) Recall the sourceRs of error and take necessary precaution. Stage 2B: PerfoIrVmin Eg Experiment or Practical. SUBLIMATNION: StudentsU should  Pour the mixture to be separated for example sodium chloride ( NaCl) and Iodine (I2) in an evaporating dish.  Cover with an inverted funnel and heat indirectly on a water bath.  Note what happens to the iodine.  Scrape off the iodine into a Petri dish. 169 Teacher assists the students PRECAUTIONS: Avoid gas leakage during heating. Be very careful when removing the funnel, so that the iodine does not mix with the sodium chloride. QUESTIONS 1 Why do we heat indirectly on a water bath? Y 2 Why do we cover with inverted funnel? AR 3 What is the application of this method in everyday life R IB Teacher assists the students L N FILTRATION: Students to DA  Put the funnel on the conical flask. A  Fold the filter paper in to four equal parts foIrmBing the shape of a funnel.  Open one end of the filter paper and puFt it inside the funnel.  Pour the mixture of the muddy di rtOy water inside the funnel.  What can you observe? Y  Note the colour of the waItTer in the conical flask. S QUESTIONS: R 1 What is inV thEe funnel? 2 Why is iIt that only the water molecules pass through the filter paper? 3 GUiveN examples of filtration apparatus we use at home. 4 What is the application in everyday life? Teacher assists the students EVAPORATION  Fill the evaporating dish with the salt solution.  Place the water- bath on the tripod stand with the fire source. 170  Place the evaporating dish on the water –bath  Watch as the water evaporates leaving the salt in the evaporating dish. Teacher assists the students QUESTIONS: 1 What happens if the mixture is heated directly? 2 Explain what happens to the solvent? 3 What is the application in everyday life? SEPARATING FUNNEL METHOD: Y  Clamp the separating funnel on the retort stand. R  Close the tap and fill it with the mixture of water and oil. A  What do you observe? BR  The mixture separates into two distinct layers. LI  Open the tap and allow the water to drain into a beaker.  Close the tap and drain the oil into another container. AN Teacher assists the students AD B QUESTIONS: I 1 Is there any difference in the densities Fof the two liquids? 2 What happens if the densities are eOqual? 3 What is the application in TeveYryday life? Teacher assists the studIents S VE R UN I 171 Y APPENDIX IIC AR HANDS-ON AND MINDS-ON PROBLEM-SOLVING MODELR (HAMPSOM) INSTRUCTIONAL GUIDE on Quantitative Analysis LIB STAGE 1A: Problem Perception. N The teacher writes the topic which is volumetric analysisA or quantitative analysis. 1B: Acquiring related theory. D The teacher teaches the studIeBnts. A There are two beakers containing Ftwo unknown solutions. The students are asked to identify each solution using red and blue litmus papers. Acid turns blue litmus paper red while Base turns red litmus paper blue. O The students are asked to defineI aTn aYcid, the definition is written as – An acid is a substance which produces hydrogen ions (or protons) as the only positive ion when dissolved in water. There are two classes of acids namelyR orgSanic acids and mineral or inorganic acids. They are asked to give examples of these acEids. Examples of organic acids are Ethanoic acid in vinegar, Lactic acid in milk, citric acidI iVn lime, lemon, and vitamin C. While the inorganic acids are Hydrochloric acid from hydrogNen and chlorine, tetraoxosulphate(VI) acid , trioxonitrate(V) acid . Strong acid ionize completUely in water to give hydrogen ions which is positively charged or cations and negatively + - charged ions or anions e.g hydrochloric acid HCL H + CL While weak acids are only partially ionized in water e.g ethaonic acid - + HCOOH COO + H , if a large quantity of water is added to a small quantity of acid, the resulting acid solution is dilute. If a little quantity of water is added to a relatively large quantity of 172 acid, the solution of the acid will be concentrated. The solution that turns blue litmus paper to red is an acid. Bases and Alkalis: The teacher asks the students explain bases and alkalis. He explains to them that the term base was originally used to describe substances that turned red litmus to blue and neutralized the properties of acids in aqueous solutions e.g oxides and hydroxides of metals Na2O, K2O, MgO. Most metallic oxides are insoluble in water, while some dissolve in water to form hydroxide Na2O(s) + H2O( l ) 2NaOH Y(aq) R Sodium oxide sodium hydroxide RA A soluble basic hydroxide is known as alkali. A strong alkalis ionize cBompletely in aqueous - I solutions to produce negatively charged hydroxide ions, OH , and positLively charged metallic ions e.g sodium and potassium hydroxides while weak alkali produce Nrela tively few ions e.g calcium hydroxide.The two solutions in the beakers are poured into Aa bigger container and tested with litmus paper. The solution formed has no effect on litmus paDper, which means it is neutral to litmus. This shows that when acid and alkali react togetherB salAt and water are formed, which is neutral to litmus paper and the reaction is known as Neutral izIation. Acid + Base Salt + water + - e.g HCL (aq) + NaOH (aq) Na CL (Oaq) +F H2O(L). Neutralization is a procYess in which an acid reacts completely with an appropriate amount of alkali (or any other baIsTe) to produce a salt and water only. + - Neutralization can also bRe deSfined as the combination of hydrogen ions, H and hydroxide ions OH to form water molecuEles, H2O. A salt is formed at the same time. So a base can beI dVefined as a substance which will neutralize an acid to yield a salt and water only. The acidUity Nand alkalinity of substances are measured using a scale of numbers from 0 to 14 known as the pH scale. A solution with a pH value of 7 is neutral i.e neither acidic nor alkaline. A solution with a pH value less than seven is acidic, while a value more than seven is alkaline. Acidity increases with decreasing pH, values while alkalinity increases with increasing pH values. 173 He explains that acid- base indicators are dyes which change colour according to the pH of the medium, Each indicator has its own specific pH range over which it changes. The pH of a solution can be measured by using universal indicator and pH meter. Indicator Methyl Orange Litmus Phenolphthalein pH range 3.1- 4.6 5.0- 8.0 8.3- 10.00 Colour change Orange Purple P a l e Pink Acid medium Red Red Colourless Alkaline medium Yellow Blue Pink Titration is the method employed in volumetric analysis. In this method, a solution wYhich is the acid from a graduated vessel is added to a known volume of a second solution, thRe base in a conical flask until the chemical reaction between the two is just completed. TRhis Ais shown by a colour change of the indicator in the resulting solution. In any titration a stanBdard solution which is one with a known accurate concentration must be used to react wiLth Ia solution of unknown concentration. The reacting volumes of the solutions are then Nused to calculate the unknown concentration of the solution. The concentration of a solutionA is the amount of solute in a given 3 3volume of the solution. It can be expressed as moldm or gdm . The concentration of a solution in 3 D moldm is the molar concentration. A molar solution Aof a compound is one which contains one 3 mole or the molar mass of the compound in one d mIB of the solution. For example the molar mass of sodium hydroxide is 40g/mol, therefore a moFlar solution of sodium hydroxide contains 1 mole or 340g of Sodium hydroxide in 1dm of the sOolution. Diagram: Y IT S R E IV N U Formulae for the calculations involving volumetric analysis. Concentration of acid Ca X Volume of acid VA = Number of moles of acid na Concentration of base CB Volume of base VB Number of moles of base nb 174 CAVA = na CB VB nb Number of moles of a substance = Number of particles = N ……………………………..(1) 23 6.02 x10 L 3 -3 Number of moles of a substance = Volume(cm ) x Concentration in moldm ………..(2) 1000 Number of moles of a substance = Mass of substance in gm Molecular mass …………………(3) Y R -3 -3 Concentration in moldm = Concentration in gdm A Molecular mass ……… RIB……..... (4) STAGE 1C: Planning experiment. L a Label the diagram. N b Using the diagram the students should identify the DappaAratus for the experiment. c Check the soundness of these apparatus. A d Students should write the sources of error IanBd the precautions to be taken. Teacher assists the students F STAGE 2A: Recalling theory. O a. Recall the sources of errorT andY take the necessary precautions. b. The teacher asks themS toI mention these sources of error and the precautions. c. He writes the sources of error and asks the students to write those that were not included in their list. ER Sources of errorI aVnd Precaution.  NRinse the burette and pipette with the solution to be used in them to avoid diluting with Uthe remains of water used in them.  Air bubbles must be removed from the burette and pipette, to obtain accurate volume of solution.  Never rinse the titration flask or conical flask with the solution it is to hold, to avoid using more solution than required. 175  Do not blow the last drop at the tip of the pipette to avoid using volume than the pipette is constructed to deliver.  The burette tap must be tight to avoid leakage.  Remove the funnel from the burette before titration commences to avoid an increase in volume of the solution in the burette.  Clamp the burette in a vertical position to avoid error due to parallax while taking the burette reading.  Shake titration flask during titration to obtain a homogenous solution. Y  Place the titration flask on a white surface to avoid over shooting the end- poRint. d. The teacher asks them to write the aim of the experiment which is the problem. RA STAGE 2B: Performing Practical B  Wash the conical flasks, burette, pipette and beakers propeLrlyI with soap solution and rinse with distilled water first, then with the solution to be poured inside each one except the conical flask. AN  Drain all the washed apparatus. D  Fill the burette with the acid to the zero markA.  Pipette the base into the conical flasksI Band add one or two drops of indicator (methyl orange). F  Record the initial volume of thOe acid.  Open the tap of the buretYte a nd run the acid into the conical flask containing the base.  Shake the mixture toI mTake a homogenous solution until there is a colour change.  Read the acid levSel in the burette and record as final level of acid.  Deduct the thRree readings and record as the volume of acid used. VE 3TiItration Reading. (Cm ) 1 2 3 N 3Final burette reading. (Cm ) A U 3Initial burette reading. (Cm ) B 3Volume of Acid used. (Cm ) X = A-B. 3 Volume of NaOH solution = 25.00cm 3 Mean volume of acid used = X cm Equation of reaction: HCL + NaOH→ NaCl + H2o. STAGE 3: OBSERVATION: 176 Students should record their observation. The teacher goes round to check their readings QUESTIONS: 1. Why do we need to clean the pipette, burette, and conical flasks? 2. Why do we rinse the pipette and conical flask with the base and the burette with the acid? 3. What is the purpose of the indicator in the experiment? 4. What is the volume of acid used each time? 5. How would you obtain the number of moles taking part in the reaction? RY 6. What is the mole ratio of the acid or base? A 3 7. Derive an expression for the concentration in mol/dm of the acid. R Teacher assists the students LI B N A AD IB APPENDFIX IIIA CONVENTIONAL METHOD (CO ONTROL) INSTRUCTIONAL GUIDE on Nature of Matter TY The teacher teaches the studeSntsI the background information first. The teacher asks the folloRwing questions. What is matteEr and what is it made up of? He explaIiVns that matter is anything that has weight and occupies space. It is made up of discrete partNicle, such as atoms and molecules. An atom is the smallest particle of an element which can takeU part in chemical reaction. The teacher asks the questions; What are a molecule and a compound? The teacher explains that a molecule is the smallest particle of a substance that can normally exist alone and still retain chemical properties of that substance either an element or compound. Elements combine to form compounds while atoms combine to form molecules. 177 The teacher asks the following question; What are physical and chemical changes? The teacher explains that a physical change is one which is easily reversed and in which no new substances are formed. Classify these into physical and chemical changes. Salt + water salt solution Wood ash +gases The teacher explains the following to the students METHOD OR PROCEDURE Weigh the crucible with the lid. RY Clean magnesium ribbon with sandpaper. A Cut 15cm of clean magnesium ribbon into the crucible. R Place the crucible on the tripod stand, heat strongly and remove the lid at inIteBrvals with the tong. When the magnesium has burned completely, remove the lid and conti nuLe heating for two minutes. Remove the crucible from the tripod stand and keep in a desiccatorN. Weigh the crucible, content and lid when it is completely cold. A Repeat heating for three minutes. Allow the crucible, coAnteDnt and lid to cool then weigh again. OBSERVATION: Students should record all observations. Repeat the experiment again and calculate the av erIaBge of the figures. RESULT: F Mass of crucible and lid= O Mass of crucible, lid and maYgne sium = Mass of crucible, lid anIdT content after heating = Mass of content = S Mass of magneRsium = Mass of oVxygEen = The teacher asksI the students the following questions (a) Write dNown known general principles and mathematical expressions that are necessary for solving tUhe problem. (b) List possible sources of error in solving the problem. (c) Recognize independent and dependent variables in the problem and note their relationship. QUESTIONS: 1) Name the elements involved in the experiment? 2) Name the compound formed? 178 3) What is the mass of crucible and lid? 4) Why do we need to clean the magnesium ribbon? 5) Why do we need to lift the lid when the magnesium was burning? 6) Why do we need to continue to heat the crucible for another 2 minutes? 7) What makes the magnesium change color? 8) What supports the burning of magnesium? 9) What is the name of the new substance? 10) How would you find out the mass of magnesium and mass of the magnesium oxide? 11) If the relative atomic mass of magnesium is 24 and oxygen is 16, how many atomsR of Y magnesium were used?. A 12) How many atoms of oxygen were used? R 13) What is the ratio of atoms of magnesium to oxygen? IB 14) Derive the formula for the magnesium oxide? L 15) Does the experiment involve physical or chemical change? N Give reason for your answer? A 16) What have you learnt from the experiment which iAs apDplicable to everyday life? 17) Is there any reason for repeating the experimenBt and why? I OF Y I T APPENDIX IIIB CONVENTIONAL MRETHSOD (CONTROL) INSTRUCTIONAL GUIDE on Separation Techniques E The teacher teacIhVes the students the following MixtuNres contain two or more different substances. Each constituent of a mixture still retains its indivUidual properties. We can take advantage of these characteristics to separate mixtures. Thus the technique employed in separating mixtures makes use of the physical properties of their constituents. 179 SUBLIMATION: Asks the students to state the states of matter. This is the direct conversion of a solid to the gaseous state directly without changing to the liquid state. Asks the students to write examples on the board. Gives example of camphor. FILTRATION: This is used to separate an insoluble solid from a liquid. This involves the use of a filter paper which is porous in nature and allows the passage of only water which is the filtrate, while the particles remain in the funnel as residue. Industries such as water purification plant and breweries use filtration to remove solid particles from liquids. Also in the purification of pipe-borne water, the water strains through the various layers of the filter bed, leaving all forms ofR susYpended materials behind. The filtered water is then treated with chemicals to kill any bacteAria in it before being piped to the consumers. R IB EVAPORATION TO DRYNESS: This method can be used to rec oLver a solid solute from a solution, the solvent escapes into the atmosphere as vapour leaviNng the solute in the evaporating dish. A Solution solute + solvent AD Evaporation can be done at a steady rate using a wIaBter bath or a sand bath. This method cannot be used to recover salts that are easily destroyFed by heating. This method is used in salt making industries. Sea water is pumped into tre nOches and allowed to evaporate under the heat of the sun along the western coast of Africa. AllY the water dries up leaving behind the salt. SEPARATING FUNNEL METIHTOD: Some liquids do not mix together; these are known as immiscible liquids e.g watSer and oil, water and petrol. Those that mix together to form a homogenous liquid aEre cRalled miscible liquids e.g water and alcohol. The immiscible liquids form two distinct layeIrVs when added together, a separating funnel can be used to separate the two layers into two diffNerent containers, the lower denser layer is collected before the less dense upper layer. The teacUher explains the following with or without diagrams SUBLIMATION:  Pour the mixture to be separated for example sodium chloride ( NaCl) and Iodine (I2) in an evaporating dish.  Cover with an inverted funnel and heat indirectly on a water bath.  Note what happens to the iodine. 180  Scrape off the iodine into a Petri dish. PRECAUTIONS: Avoid gas leakage during heating. Be very careful when removing the funnel, so that the iodine does not mix with the sodium chloride. QUESTIONS 1 Why do we heat indirectly on a water bath? Y 2 Why do we cover with inverted funnel? R 3 What is the application of this method in everyday life. BR A FILTRATION: LI  Put the funnel on the conical flask.  Fold the filter paper in to four equal parts forming the shAapeN of a funnel.  Open one end of the filter paper and put it inside theD funnel.  Pour the mixture of the muddy dirty water iside tAhe funnel.  What can you observe? IB  Note the colour of the water in the coniFcal flask. O QUESTIONS: 1 What is in the funnel? TY 2 Why is it that only thSe wIater molecules pass through the filter paper? 3 Give examples ofR filtration apparatus we use at home. 4 What is the apEplication in everyday life EVAPORATIOINV  Fill tNhe evaporating dish with the salt solution.  PUlace the water- bath on the tripod stand with the fire source.  Place the evaporating dish on the water –bath  Watch as the water evaporates leaving the salt in the evaporating dish. QUESTIONS: 1 What happens if the mixture is heated directly? 181 2 Explain what happens to the solvent? 3 What is the application in everyday life? SEPARATING FUNNEL METHOD:  Clamp the separating funnel on the retort stand.  Close the tap and fill it with the mixture of water and oil.  What do you observe?  The mixture separates into two distinct layers. Y  Open the tap and allow the water to drain into a beaker. R  Close the tap and drain the oil into another container. A R OUESTIONS: IB 1 Is there any difference in the densities of the two liquids? L 2 What happens if the densities are equal? N 3 What is the application in everyday life? D A IB A OF ITY S VE R I N APPENDIX IIIC U CONVENTIONAL METHOD (CONTROL) INSTRUCTIONAL GUIDE on Quantitative Analysis The teacher teaches the student the following. There are two beakers containing two unknown solutions. The students are asked to identify each solution using red and blue litmus papers. Acid turns blue litmus paper red while Base turns red litmus paper blue. The students are asked to define an acid , The definition is written as – An 182 acid is a substance which produces hydrogen ions (or protons ) as the only positive ion when dissolved in water. There are two classes of acids namely organic acids and mineral or inorganic acids. They are asked to give examples of these acids. Examples of organic acids are Ethanoic acid in vinegar, Lactic acid in milk, citric acid in lime, lemon, and vitamin C. While the inorganic acids are Hydrochloric acid from hydrogen and chlorine, tetraoxosulphate(VI) acid , trioxonitrate(V) acid . Strong acid ionize completely in water to give hydrogen ions which is positively charged or cations and negatively charged ions or anions + - e.g hydrochloric acid HCL H + CL . Y While weak acids are only partially ionized in water AR - + e.g ethaonic acid HCOOH COO + H , if a large quantity oRf water is added to a small quantity of acid, the resulting acid solution is dilute. If a little quaLntiItyB of water is added to a relatively large quantity of acid, the solution of the acid will be con centrated. The solution that turns blue litmus paper to red is an acid. AN Bases and Alkalis: The term base was originally useDd to describe substances that turned red litmus to blue and neutralized the properties ofB acAids in aqueous solutions e.g oxides and hydroxides of metals Na2O, K2O, Mg. Most metIallic oxides are insoluble in water, while some dissolve in water to form hydroxide F Na2O(s) + H2O(l) 2NaOHY (aq) Sodium oxide I sTodium hydroxide A soluble basic hRydrSoxide is known as alkali. A strong alkalis ionize completely in aqueous -solutions to produce Enegatively charged hydroxide ions, OH , and positively charged metallic ions e.g sodium andI pVotassium hydroxides while weak alkali produce relatively few ions e.g calcium hydroxide. N The twoU solutions in the beakers are poured into a bigger container and tested with litmus paper. The solution formed has no effect on litmus paper, which means it is neutral to litmus. This shows that when acid and alkali react together salt and water are formed, which is neutral to litmus paper and the reaction is known as Neutralization. Acid + salt water + - e.g HCL (aq) + NaOH (aq) Na CL (aq) + H2O(L). 183 Neutralization is a process in which an acid reacts completely with an appropriate amount of alkali (or any other base) to produce a salt and water only. + - Neutralization can also be defined as the combination of hydrogen ions, H and hydroxide ions OH , to form water molecules,H2O. A salt is formed at the same time. So a base can be defined as a substance which will neutralize an acid to yield a salt and water only. The acidity and alkalinity of substances are measured using a scale of numbers from 0 to 14 known as the pH scale. A solution with a pH value of 7 is neutral i.e neither acidic nor alkaline. A sYolution with a pH value less than seven is acidic, while a value more than seven is alAkaliRne. Acidity increases with decreasing pH, values while alkalinity increases with increasing pRH values. Acid- base indicators are dyes which change colour according toI tBhe pH of the medium, Each indicator has its own specific pH range over which it changes. ThLe pH of a solution can be measured by using universal indicator and pH meter. N Indicator Methyl Orange Litmus DA Phenolphthalein pH range 3.1- 4.6 5.0- 8.A0 8.3- 10.00 Colour change Orange PIuBrple P a l e Pink Acid medium Red F Red Colourless Alkaline medium Yellow O Blue Pink Titration is the method emTploYyed in volumetric analysis. In this method, a solution which is the acid from a graduated veSsseIl is added to a known volume of a second solution , the base in a conical flask until the cRhemical reaction between the two is just completed. This is shown by a colour change of the Eindicator in the resulting solution. In any titration a standard solution which is one with a knoIwVn accurate concentration must be used to react with a solution of unknown concentratioNn. The reacting volumes of the solutions are then used to calculate the unknown concentrUation of the solution. The concentration of a solution is the amount of solute in a given 3 3volume of the solution. It can be expressed as moldm or gdm . The concentration of a solution in 3 moldm is the molar concentration. A molar solution of a compound is one which contains one 3 mole or the molar mass of the compound in one dm of the solution. For example the molar mass of sodium hydroxide is 40g/mol, therefore a molar solution of sodium hydroxide contains 1 mole 3 or 40g of the hydroxide in 1dm of the solution. Formulae for the calculations involving volumetric analysis. 184 Concentration of acid Ca X Volume of acid VA = Number of moles of acid na Concentration of base CB Volume of base VB Number of moles of base nb CAVA = na CB VB nb Number of moles of a substance = Number of particles = N ………………..(1) 23 6.02 x10 L 3 -3 Number of moles of a substance = Volume(cm ) x Concentration in moldm …..(2) 1000 RY Number of moles of a substance = Mass of substance in gm ………………(A3) Molecular mass R -3 -3 Concentration in moldm = Concentration in gdm ………I…B..... (4) Molecular mass LN Sources of error and Precaution. A  Rinse the burette and pipette with the solutioAn tDo be used in them to avoid diluting with the remains of water used in them.  Air bubbles must be removed from th e IbBurette and pipette, to obtain accurate volume of solution. F  Never rinse the titration flas kO or conical flask with the solution it is to hold, to avoid using more solution than Yrequired.  Do not blow the lastI dTrop at the tip of the pipette to avoid using volume than the pipette is constructed to Sdeliver.  The bureEtte tRap must be tight to avoid leakage.  RemoVve the funnel from the burette before titration commences to avoid an increase in voluIme of the solution in the burette. U NClamp the burette in a vertical position to avoid error due to parallax while taking the burette reading.  Shake titration flask during titration to obtain a homogenous solution.  Place the titration flask on a white surface to avoid over-shooting the end- point. The teacher asks the students to do their titration and answer the questions 3 Titration Reading. (Cm ) 1 2 3 185 3 Final burette reading. (Cm ) A 3 Initial burette reading. (Cm ) B 3 Volume of Acid used. (Cm ) X = A-B. 3 Volume of Base solution = 25.00 / 20.00 cm 3 Mean volume of acid used = X cm a Write the equation of the reaction. b Write your observations. Y QUESTIONS: AR 1. Why do we need to clean the pipette, burette, and conical flasks? R 2. Why do we rinse the pipette and conical flask with the base and the bIuBrette with the acid? 3. What is the purpose of the indicator in the experiment? L 4. What is the volume of acid used each time? N 5. How would you obtain the number of moles taking partA in the reaction? 6. What is the mole ratio of the acid or base? D 3 7. Derive an expression for the concentration inB moAl/dm of the acid. F I O ITY S VE R I UN APPENDIX 1V ANSWERS TO QUESTIONS IN APPENDICES A 186 1 Magnesium and Oxygen 2 Magnesium Oxide 3 This depends on the mass obtained in each of the experimental group because we have different sizes of crucible. 4 We need to clean the dust and impurities on the magnesium ribbon so as not to increase the mass. 5 We need to lift the lid when the magnesium is burning so that air which contains oxygen can flow into the crucible. RY 6 We need to continue to heat the crucible for another two minutes afteAr it has burnt completely, so that the magnesium oxide will be free of other gases preseRnt in the air. 7 The colour changed because the magnesium ribbon has combineIdB with oxygen to form another compound which is magnesium oxide. L 8 Oxygen supported the burning of magnesium. N 9 The name of the new substance is magnesium oxide. A 10 The mass of the magnesium can be obtained froAm Dsubtracting the mass of crucible and lid from the mass of crucible lid and magnesium. The mass of the magnesium oxide can als oI bBe obtained by subtracting the mass of crucible with lid from the mass of crucible, lid aFnd content after heating. 11- 14 These can be calculated using thOe masses obtained during the experiment. 15 The experiment involves a chemYica l change, because the magnesium oxide produced is different from the magnesiuImT ribbon and the magnesium ribbon can not be obtained again. 16 From the experiment wSe can derive the formula of magnesium oxide. This shows that oxygen is present in the air sustaRining the life of animals without which we cannot be alive. The oxygen is not only used foVr brEeathing by animals but can combine with other elements and form another product. I 17 There is Nneed to repeat the experiment if there is no change in colour and mass of magnesium ribbon. TUhis shows that the reaction between magnesium and oxygen has not occurred or there is a faulty apparatus. APPENDIX V 187 ANSWERS TO QUESTIONS IN APPENDICES B SUBLIMATION 1 We need to heat indirectly on a water bath so that we do not loose some of the materials when the heating is direct and too much. 2 We covered the evaporating dish with an inverted funnel so that the rate at which the gas is escaping can be reduced at the narrow end of the funnel which leads to condensation of the gas. This allows us to regain our iodine instead of escaping into the atmosphere. 3 At home we make use of elements and compounds which change from solid directlRy toY gas for example camphor. The odour in gaseous state send away cockroaches and other iAnsects that can destroy our books, dresses and food away. R IB FILTRATION L 1 The residue which is the solid particle (solute) is in the funnel. N 2 Only the solvent passes through the filter paper, because the soAlute is bigger in size than the pores of the filter paper. D 3 Examples of filtration apparatus used at home are sievAe with pores of different sizes and clean cloth. IB 4 We can use the method to remove suspendedF particles from our water, also can be used to remove big particles from our yam flour, cassa vOa flour, pap and stones from food items. EVAPORATION ITY 1If the mixture is heated RdireSctly the rate of evaporation will increase and some of salt can be lost when evaporation iEs almost completed. 2 The solvent chIaVnges to gaseous state and the molecules escape into the atmosphere. 3 ApplicatioNn everyday life is that when we cook or fry food, we should not use high flame. Also if there Uis too much water in the food or soup, we can concentrate or remove the water by evaporation. It is also useful in the industries. SEPARATING FUNNEL METHOD 1 Yes there is difference in the densities of the two liquids 2 We will use another method for the separation. 188 3 If we mistakenly pour two liquids together e.g palm oil or ground nut oil with water or kerosene with water. We can easily separate them due to their differences in density. We can carefully pour each into different containers not necessarily using the separating funnel. It is also used in industries. RY A IB R N L DA BA I OF Y IT RS E IV UN 189 APPENDIX V1 ANSWERS TO QUESTION IN THE APPENDICES C 1 We need to wash the apparatuses because of impurities which can affect the volume of acid used. 2 These are the solutions that should be poured in to these apparatuses. 3 The indicator changes colour at the end point (showing the end of the reaction). 4 The volume of the acid used is the subtraction of the initial volume of the burette fYrom the final reading of the burette. R 5 This is from a balanced equation of the reaction. A 6 This is the ratio of the mole of the acid to the mole of the base in thBe baRlanced equation of the reaction. I 7 CA VA / CB VB = NA / NB L CA VA N N B = CB VB NA A CA = CB VB NA / VA NB Where AD 3 CA = concentration of Acid in mol/dm IB 3 CB = concentration of Base in molF/dm O3VA = volume of the Acid in cm obtained during titration 3 VB = volume of the BaseY in cm this is the volume of the pipette NA = the number ofI mToles of the acid obtained from the balanced equation of the reaction N SB = the numRber of moles of the base obtained from the balanced equation of the reEaction 8 This is useNful Im Vostly in the industries where precise amount of substances are needed. U 190 APPENDIX V11 INTERNATIONAL CENTRE FOR EDUCATIONAL EVALUATION INSTITUTE OF EDUCATION UNIVERSITY OF IBADAN IBADAN. CHEMISTRY ACHIEVEMENT TEST (CAT) Y Dear Respondent, R This test is for research purposes. Please shade the appropriate answer lettereAd A-D to each question in the answer sheet provided. Thank you. R 1. The relative molar mass of Magnesium(II) tetraoxosulphate(VI) is A.72I B B.120 C.140 D.240 ( Mg=24, S=32,O=16) L 2. In which of these equations will the number of molecules of rNeactant and products remain the same? A A. Ag NO3 + BaCl2 AgCl + Ba(NO3) D B. Fe + H2O Fe3O4 + H2O A C. CaCO3 CaO + CO2 IB D. H2S +O2 H2O + SO2 F 3. A compound has a chemical formula MO2(SO4)3. The combining power of M is A.6, B. 5, C.3, D.2 Y 4. What is the percentage by massT of Calcium in Calcium trioxocarbonate (IV)? (Ca=40, C=12, O=16)S. I A. 80%, B.58% , C. 52%, D.40%. 5. The chemical formulaR for zinc oxides is A. ZnO2, B.V ZnE2O2, C. Zn2O, D. ZnO. 6. CuSO4. 5H2OI means A. 1 atomN Cu, 1 atom of S, 5 atoms of O and 2 atoms of H. B. 1 aUtom of Cu, 1 atom of S, 9 atoms of O and 2 atoms of H. C. 1 atom of Cu, 1 atom of S, 5 atoms of O and 10 atoms of H. D. 1 atom of Cu, 1 atom of S, 9 atoms of O and 10 atoms of H. 7. Silver Oxide was heated strongly to produce Silver and Oxygen. The chemical equation for the reaction is: A 2Ag2O Ag + O2 191 B. 2Ag2O 4Ag + O C. 2Ag2O 2Ag2 + O D. 2Ag2 O 4Ag + O2 8. A compound with empirical formula CH2O and a molecular formula of 90 g mo1-1. What is the molecular formula of the compound? (C=12, H=1, O=16) A. 3CH2O B. C3H6O3 C. (CH2O)3 D. C3(H2O)3. 9. 7g of iron reacts with 8g of Sulphur to form Iron(11) Sulphide. Calculate how much of Sulphur was left unused ? The equation of the reaction is : Fe + S FeS (Fe = Y56, S = 32). A. 2, B. 3, C. 4, D. 6. 3 R 10. A solution of sodium trioxocarbonate (1V) contains 10.6g in 250cm of solution.A Calculate the concentration of the solution. [Na2CO3 = 106.0]. R 3 3 3 3 A. 0.4 mol/dm , B. 1.0 mol/dm , C. 10.6 mol/dm , D.25.0 mol/dm . IB 11. The numerical coefficients in a balanced equation give A. the n uLmber of moles of reactants and products, B. the molar mass of the reactants and products, CN. the number of moles reactants Only, D. the molar mass of the products only. A 2- 12.The number 0f moles of SO4 in K2SO4. Cr2(SO4)3 . A24HD2O is A. 4, B. 5, C, 6, D. 8. 2+13. How many moles of copper ions (Cu ) are there in 0.2 mol CuSO4 ?. 2+ 2- CuSO4 Cu + SO4 AI, B 0.1, B. 0.2, C. 0.4, D. 2.0. 14. In a chemical reaction one mole of FeclF3 solution reacts completely with 3 moles of NaOH 3 solution. What volume of 1M NaOH sol uOtion will be required by 50cm of 1M Fecl3 solution. 3 3 3 3 A. 150cm , B. 100cm , C. 5Y0cm , D. 25cm . 15. What is the mass in gram ofI sTolute in 1M NaCl?. (Na = 23, CL = 35.5). A. 585g. B, 58.5g, S C. 5.85g, D. 0.585g. 16. Vaseline does not fRlow like kerosene because: A. Vaseline particles are thicker than kerosene particles. B. VEaseline particles form a solid at room temperature. C. Vaseline particles are held closer than IkVerosene. D. Vaseline particles are heavier than kerosene. 17. Iron filNlings can be separated from chalk particles by A.U Magnetization, B. Decantation, C. counting, D. blowing. 18. Sieving method is employed in A. gari industry, B. soap Industry, C. salt making industry, D. gas industry. 19. Components of crude oil are best separated by A. Fractional distillation B. Fractional crystallization C. Distillation D. Evaporation. 20. A mixture of sand and iodine can be separated by 192 A. filtration B. sublimation C. crystallization, D. sedimentation. 21. The component colours of a leaf can be separated by A. colour extraction, B. centrifugation, C. boiling, D. chromatography. 22. A mixture of salt and sand can be separated by A. dissolution, filtration and evaporation, B, Filtration, dissolution and evaporation C. evaporation, dissolution and filtration, D, Dissolution, evaporation and filtration. 23. Which of the following techniques is used in town water supply? A Crystallization B. filtration C. distillation D. fractional distillation. 24 The process of spinning insoluble solute in a solution at high speed is called RY A. Distillation, B. spinning, C. centrifugation, D. magnetization. A 25. The apparatus needed in a filtration process include R A. Conical flask, funnel, filter paper, B. beaker, funnel, sieve, C. CIonBical flask, funnel, sieve, D. beaker, funnel, filter paper L 26. One of the following is not a criteria for purity N A. Atomicity, B. density, C. boiling point, D. meAlting point. 27. A mixture in which the constituents can easily be distingDuished is said to be A. Homogenous, B. miscible, C. HeterogeneouAs, D. Immiscible, 28. Principles which separation of mixtures are ba sIedB include the following except A. particle size, B. atomic mass, C. mFagnetic property, D. solubility. 29. When a solid body is heated it expan dOs. Which is the most satisfactory explanation? A. the molecules get bigger, Y B. the heat energy is converted into extra mass, C. the space between the mIoTlecules increases, D. the molecular vibration decreases. 3 30. How many mole of AgSNO3 are there in 500 cm of 0.01M AgNO3 solution ?. A. 5 mole, B.R 0.5 mole, C. 0.05 mole, D. 0.005 mole. IV E UN 193 APPENDIX V111 ANSWERS TO THE CHEMISTRY ACHIEVEMENT TEST Y 1. B 2. C AR 3. C 4. D BR 5. D LI 6. D 7. D N 8. B DA9. C 10. A A 11. A 12. A IB 13. C F 14. A 15. B O 16. C Y 17. A T 18. A I 19. A 20. B RS 21. D E 22. A V 23. B NI24. C 25U. A 26. A 27. C 28. B 29. C 30. D 194 APPENDIX 1X Y INTERNATIONAL CENTRE FOR EDUCATIONAL EVALUATION, R INSTITUTE OF EDUCATION, U. I. IBADAN. RA STUDENTS’ ATTITUDETO PRACTICAL CHEMISTRY SCIABLE (SAPCS) Dear Respondent, L This questionnaire is for research purpose. Please tick wNhere you feel it is appropriate. Thank you. A Please note: SA means Strongly Agree; A meaAns D Agree; D means Disagree SD means Strongly Disagree B School:…………………………………F…… I………………………………………………………………………………………. Number in class: ………… OY…. . ITEMS IT SA A D SD 1 The chemistry class is alwaSys boring. 2 It is interesting readingR chemistry topics than working problems. 3 When a problemV caEnnot be solved immediately, it is better to keep solving it untiIl ones gets it. 4 It is goUod Nto play games that help in solving problems in practical chemistry. 5 When challenged by situations one cannot immediately understand, one should try to read to solve the problem. 6 Solving different types of problems is interesting. 7 Games which demand rigorous thinking are bad. 8 Most of my friends are as good as myself in solving problems. 195 9 When a question is left unanswered in the class, one should continue thinking about it. 10 It is better to have a friend who can tell you the solution to a difficult problem than to work it out yourself. 11 Puzzle books are interesting you find it difficult to leave it once you pick it up. 12 keeping record of games when others are playing is enjoyable. 13 Mathematics is one of my best subject. Y 14 When instructions are not very clear, one should find a way to solve the problem AR 15 Thinking about problems is my hobby. R 16 Chemistry practical is too mathematical for my liking. IB 17 It is enjoyable working with different chemistry apparatus. L 18 One does not need much practical chemistry to have a good gradNe in Chemistry. A 19 Linking theory with practical is very easy. D 20 It is better for the teacher to demonstrate experimIBents A than students performing it. 21 Minimum instruction should be given iOn soFlving practical chemistry problem. 22 Instructions in the practical maTnuaYl should be followed strictly. 23 A good knowledge of chemisItry practical, shows good knowledge of chemistry. S 24 Students who partEicipRate in practical chemistry develop interest in chemistry. 25 Previous VNknoIwledge is needed to solve problems in practical chemUistry. 26 It is important to understand problem before solving it in practical chemistry. 27 One should review the related principles of the problem problems in practical chemistry. 28 A job that needs thinking is better than one which does not need 196 thinking. 29 The teacher‟s experiment demonstration helps develop interest in chemistry practical. 30 The Technological progress could not be without practical chemistry. Y APPENDIX X R A QUESTIONS ON THE PRACTICAL FOR THE CHEMISTRY PROCESS SKILL RATING SCALE (CPSRS) IB All your burette readings initial and final must be recorded L 3 A is a solution containing 1.04g HCl per 500cm of solution. NB was prepared by diluting 3 3. 50.0cm of a saturated solution of NaOH at room temperaAture to 1000cm 3 a Put A into the burette and titrate it against 2A5cmDportion of B using methyl orange as indicator. Repeat the titration to obtain consIisBtent titres. Tabulate your results and calculate the average volume of acid used. b From your results and the informatioFn provided above , calculate the 3 i concentration of A in mol/dYm O 3 ii concentration of B in mol/dm The equation of the reactioInT is: HCl + NaORH S NaCl + H2O [H=E 1, O = 16, Na = 23, Cl = 35.5 ] V I N U 197 RY A APPENDIX X1 R INTERNATIONAL CENTRE FOR EDUCATIONAL EVLAILBUATION INSTITUTE OF EDUCATION ,UNIVERSITY OF INBA DAN, IBADAN. CHEMISTRY PROCESS SKILLS RATDINGA SCALE(CPSRS). Key V - Very Poor A P - Poor IB F - Fair F G - Good O E - Excellent TY Skill Category BSehaIviour Category VP P F G E A.Manipulative i ARdherence to instructions to carry out a full Skills and conduct E range of experiments/ activities. of experiments NI V ii Use of relevant/ correct apparatus(es) for U given activities. iii Correct handling of apparatus. Iv Use of reasonable time to set up experiment v Set up of experiment accurately vi Ability to discharge drops 198 B.Controlling i Adopt strategies to prevent uncontrolled Extraneous changes in the amount of measured materials Variables during experiment,(through leaking, spilling) ii Wash up apparatuses to prevent contamination and misleading observation. iii Use only two drops of indicator to avoid masking of end point during titration experiment. Y iv Record measured quantities accurately. R v Use average titre values for calculations A during volumetric analysis. R C. Measurement i Select correct measuring instrument/ I B skills apparatus for measuring a given substance. L ii Estimate quantity of chemical substances N (volumes, masses) A iii Accurately read the liquid in buretteD or measuring cylinder. A iv Accurately pipette the liq uIidB into the conical flask. F D. Work Habit i Self reliance in ca rrOying out experiment. ii Honestly recoYrd observation/ data. iii Self reliIanTce in analysis of data. iv NeatSness of report. Ev WRash up apparatus after use. IV vi keep work space orderly. N vii Dispose waste/ effluents correctly(solid U wastes in trash basket and liquids in the sink). viii keep laboratory clean. E. Safety Skill i Adopt strategies to avoid exposing self or mate to laboratory accident. ii Adopt organized movement in the 199 laboratory. iii Avoid obstruction of passage way for free movement of students/ staff. iv Avoid damage/ accident to laboratory apparatus F.Mathematics i Ability to find average of repeated quantitative data e.g titre values. ii Understand the basic formulae for Y computation of concentrations. R iii Set up relevant mathematical equations A relating known and unknown. R iv Ability to effect changes of subject in a I B mathematical equation in order to find the L unknown. N v Ability to substitute data that has been A generated from experiment into equaDtion. Vi Details and accuracy of coImBput Aations. vii Adjust values to suitable significant figures F H.Observation, i Use correct units o fO measure to express Recording of data quantitiesT. Yandcommunication I ii RecoSgnise end point/ equivalent point of E Rtitration experiment. V iii Organise data in the in the appropriate NI tabular format. U iv Record Data/ Observation accurately. 200 RY BR A I L APPENDIX X11 AN ANSWER TO THE QUESTIONS ON CHEMISTRYD PROCESS SKILLS SCALE The students were rated as they perform the titratioIn.B Th Ae titre value is the same for each experimental group and different from other group s. This is because the sources of water and the chemicals are different. F Calculations. Y O 3 i Concentration of A in mol/dmI T 3 From the question 1.04g Rof HSCl per 500 cm 3 This means that 5V00 cEm contains 1.04g 3 3 1000cm wiNll coIntain 1000/500 x 1.04 = 2.08g/dm 3 3 ConcentUration in mol/dm = Concentration in g/dm / molecular mass. Molecular mass of HCl = 1+ 35.5 = 36.5 g/mol 3 Concentration in mol/dm = 2.08/ 36.5 = 0.0569 3 Concentration of B in mol/dm 201 CA VA / CB VB = NA / NB CA VA NB = CB VB NA CB = CA VA NB / VB NA Where 3 CA = concentration of Acid in mol/dm 3 CB = concentration of Base in mol/dm Y 3 VA = volume of the Acid in cm obtained during titration AR 3 VB = volume of the Base in cm this is the volume of the pipette BR NA = the number of moles of the acid obtained from the balanced e qLuaItion of the reaction NB = the number of moles of the base obtained from the baAlancNed equation of the reaction CA VA / CB VB = NA / NB D 0.0569 x VA / CB x 25 = 1/1 BAI CB = 0.0569 x VA x 1 / 25 x 1 F This was be calculated for each experime nOtal group when the value of the average volume of acid used was obtained for each group TandY substituted. I ER S IV N U 202 Y AR LIB R N DA APPENDIIXB X A111 INTERNATIONAL CENTRE FFOR EDUCATIONAL EVALUATION INSTITUTE OF EDUCAT IOON ,UNIVERSITY OF IBADAN, IBADAN. LABORATORTY YINVENTORY CHECK LIST (LICL). Dear Sir/Ma, I ThRis iSs for research purposes. Please tick ( ) the appropriate column for the availability of the appEaratus in your school. Thank you. Name of school:I…V…………………………………………………………………………………. QualificatioNns:……………………………………………………………………………………… NumberU of years spent in the school:………………………………………. APPARATUS A V A I L A B L E NOT AVAILABLE 1 Flat bottomed flask 2 Round bottomed flask 3 Conical flask 4 Test tubes 203 5 Boiling tubes 6 Beakers 7 Evaporating dishes 8 Separating funnel 9 Funnels 10 Filter papers 11 Retort stands 12 Glass rods Y 13 Tripod stands R 14 Bunsen burner A 15 Gas (any source of heat) R 16 Liebig‟s condenser IB 17 Crucible with lid L 18 Pipe clay triangle or wire gauze N 19 Micro test tubes A 20 Combustion tube D 21 U tube A 22 Thistle funnel IB 23 Connecting tubes F 24 Weighing balance O 25 Ethanol TY 26 Sodium chloride I 27 Magnesium ribbonS 28 Mineral AcEidsR: HCL,H2SO4 29 BasesI: VNaOH, Na2CO3. UN 6 204 RY RA B LI AN D BA I APPEND FIX X1V PHOTOGRAPHS OF STUDENTS W ORKING IN THE LABORATORY DURING THE RESEARCH ITY RS IV E UN 205 Y AR LIB R AN D BA OF I ITY RS IV E UN 206 Y AR LIB R AN ADB F I Y O ITS VE R UN I 207 RY RA LI B N AD A IB OF ITY S VE R I UN 208