This study examined the effects of computer-based multimedia instructional packages on the academic achievement of students offering Biology in Senior Secondary Schools in Ibadan, Oyo State, Nigeria. Two multimedia instructional packages were designed for the study. The study adopted the pretest-posttest, control group, experimental research design. The population of the study consists of 80 randomly selected students from three secondary schools in Ibadan, Oyo State, Nigeria. The samples were randomly assigned to three groups (one control and two experimental groups). The moderating effects of gender and learning styles were also tested. The results showed that there was a significant main effect of treatment on students' achievement in Biology (F (2, 58) = 27.18; P < 0.05; partial eta square = 0.48). Also, gender had no significant main effect on students' performance (F (1, 58) = 3.97; P > 0.05; Partial eta square = 0.06). It was therefore concluded that multimedia instructional packages significantly enhanced students learning of Biology concepts than the conventional strategy, regardless of gender and the preferred learning style of students. Therefore, it was recommended that more multimedia instructional packages be designed and used in secondary schools for effective and efficient teaching and learning of Biology.
Keywords: multimedia instructional packages, academic achievement, Biology, teaching strategy, learning styles, gender