Abstract
The study investigated the effect of constructivist teaching approach on academic achievement of senior secondary two (SSS 2) biology students in Numan Education Zone of Adamawa State. The study also determined the interaction effect between the approach and gender on students’ academic achievement. Three research questions and three null hypotheses formulated and tested at 0.05 level of significance guided the study. The study adopted a quasi-experimental, pretest, posttest, non-equivalent control group design with 2 x 2 factorial matrix. The sample consisted of 231 SSS 2 biology students drawn from four intact classes selected by simple random sampling technique. Instrument for data collection was a 40 item Biology Achievement Test adopted from WAEC past question papers from 2010 to 2015. The instrument was both face and content validated. The reliability of the instrument was determined with K-R 20 method and an internal consistency reliability coefficient of 0.79 was obtained. Mean and standard deviation were used to answer the research questions while ANCOVA was used to test the hypotheses. Findings of the study indicated that there is significant difference between the performance of Biology students exposed to constructivist teaching approach and conventional lecture method in favour of the constructivist (experimental) group; male students performed better than the female students in the study; there was no interaction effect between treatment and gender on students’ academic achievement. It was recommended among others that constructivist teaching approach be used in teaching biology.