EFFECTS OF PROBLEM-BASED AND TEXTBOOK-WITH-ASSESSMENT APPROACHES ON SECONDARY SCHOOL CHEMISTRY STUDENTS' LEARNING OUTCOMES IN FEDERAL GOVERNMENT COLLEGES, SOUTH-WEST, NIGERIA

Abstract

Enrolment pattern and achievement in Chemistry over the years appears not to have reflected the importance of the subject in the scientific and technological development of the nation. This problem is attributed to poor teaching/learning methods used in schools. However, there is the need to study possible effects of student-centred strategies on learning outcomes in Chemistry. This study, therefore, investigated the effects of three model teaching methods; Problem-Based (PB), Textbook-with-Assessment (TwA), and combination of PB and TwA learning approaches on academic achievements and practical skills of secondary school Chemistry students in South-West, Nigeria. The study adopted pretest and posttest control group in quasi-experimental setting with 4x3x2 non- randomized factorial design. Opportunity-To-Learn (OTL) and school type were used as moderator variables. Two hundred and eighty-one senior secondary school two Chemistry students drawn from four single-sex and four co-educational Federal Government Colleges participated. Treatments were randomly assigned to groups. For instance, PB was used by group one, TwA was used by group two, PB and TwA was used by group three while conventional method was used by the control group. Chemistry Achievement Test (r = 0.78), Chemistry Manipulative Skill Scale (r = 0.87) and Students' Questionnaire for Assessment of OTL (r = 0.79) were used for collection of data. Chemistry Treatment Manuals were used as guide for teaching in each of the three experimental groups and the control. Descriptive statistics, Analysis of Covariance and Scheffe Post Hoc Multiple Comparison were used to analyse data at 0.05 level of significance. Learning approaches had significant effect on students' academic achievement (F(3,262)=15.88) and practical skills in Chemistry (F (3,262) = 211.59). Problem-Based group scored highest (x ?=29.38), followed by combination of PB and TwA group (x ?= 27.97), and TwA group (x ?=25.64), while the conventional group had the lowest score (x ? =25.06) in academic achievement. In practical skills, combination of PB and TwA group scored highest (x ? = 118.99), followed by TwA group (x ? = 114.32), PB group (x ?= 110.75) with conventional group scoring the least (x ? =81.47). School type (F1,262 =38.29) had significant main effect on practical skills but not on academic achievement. Opportunity-To-Learn showed no significant main effects on academic achievement and practical skills. However, the three learning approaches and OTL had no significant improvement on academic achievement and practical skills. Treatment and school type had interaction effects on academic achievement (F1,262=6-911) and practical skills (F1, 1,262= 8.424). Interaction effects of treatment, OTL and school type showed no significant improvement on either academic achievement or practical skills. Problem-based and Textbook-with-Assessment learning approaches improved the academic achievement of students in Chemistry irrespective of the effect of OTL and school type. Teachers in co-educational colleges, when teaching practical Chemistry, should emphasize its importance to students' understanding of the theory and to improve their examination scores.