Effect of Problem-Based Learning on Students’ Critical Thinking Skills in Biology in Anambra State Secondary Schools

This study investigated the effect of problem-based learning on the critical thinking skills of Biology students in secondary schools in Anambra State, Nigeria. The development of critical thinking is increasingly identified as a core outcome of quality Science education, yet many Nigerian Biology classrooms continue to prioritise rote learning over analytical skill development. A quasi-experimental pretest-posttest control group design was employed. Six intact SS2 Biology classes from six government secondary schools in Awka South and Onitsha North Local Government Areas were randomly assigned to experimental and control conditions. The experimental groups received instruction through structured problem-based learning scenarios drawn from local ecological contexts, while control groups followed conventional lecture-based teaching. A validated Critical Thinking Skills Test in Biology was used as the instrument, with a reliability coefficient of 0.83. Analysis of Covariance was used to analyse the data. Results showed that students in the problem-based learning group recorded significantly higher critical thinking scores than the control group. No significant gender interaction effect was observed. The findings supported the adoption of problem-based learning as an effective instructional approach for fostering higher-order thinking in Biology education. Recommendations included curriculum revision to embed problem-based tasks and teacher training in facilitation techniques. Keywords: problem-based learning, critical thinking, Biology education, Anambra State, secondary schools.