Study of the Effect of Problem-Based Learning on Achievement in Chemistry Among Senior Secondary Students in Plateau State

Problem-based learning engages students in the active application of scientific concepts to authentic problems, and empirical evaluation of its effectiveness in Chemistry teaching in North Central Nigerian secondary schools provides evidence for science education reform. This study investigated the effect of problem-based learning on the academic achievement of SS2 Chemistry students in Jos North Local Government Area, Plateau State, North Central Nigeria. A quasi-experimental pre-test and post-test design was employed, with 70 students in the PBL experimental group and 70 in a conventional instruction control group. Both groups studied the same Acids, Bases, and Salts unit over six weeks. Achievement tests aligned with WAEC Chemistry objectives were administered before and after instruction. Pearson correlation and independent samples t-test were applied. The PBL group showed a significantly higher mean post-test score (73.2) than the control group (60.7, p < 0.001). The effect size was large (Cohen's d = 1.14). PBL students showed significantly higher scores on application and analysis items than on knowledge-recall items, while control group scores showed the reverse pattern. The study concludes that PBL significantly improves Chemistry achievement among Plateau State secondary students and recommends PBL training workshops for Chemistry teachers, provision of laboratory materials for inquiry activities, and revision of Chemistry curriculum guides to explicitly include PBL activity structures. Keywords: problem-based learning, Chemistry achievement, secondary school, Plateau State, science education