Philomena N. Okafor

The study investigated the comparative effectiveness of the expository and concept mapping instructional strategy of presenting secondary school biology concepts to slow learners. One hundred and twenty four biology slow learners were identified and randomly assigned to the expository group (n=62) and concept mapping group (n=62) and respectively taught the concept of photosynthesis. The groups were post-tested after two weeks of teaching for any significant differences in their biology achievement. Analysis of post-test scores indicated that the group taught by the concept mapping instructional strategy performed significantly (p<0.05) better than their expository group counterparts. Specifically, female slow learners taught with the concept mapping instructional strategy performed significantly (p<0.05) better than their male counterparts taught by the same method. These results have implications for biology teacher preparation, especially in the areas of teaching females and identifying slow learners and adopting effective methods of tackling their problems