Comparative Effects of Problem-Based Learning and Programmed Instruction on Academic Achievement of Senior Secondary School Students in Biology

This study investigated the comparative effects of Problem-Based Learning (PBL) and Programmed Instruction (PI) strategies on the academic achievement of senior secondary school students in Biology. A quasi-experimental pretest-posttest control group design was employed, involving 225 Senior Secondary ll students drawn from public schools in Lagos District II (Kosofe,lkorodu & Somolu), Lagos state, South-western Nigeria. The students were randomly assigned to one of three groups: PBL, PI, and a Control group taught with the conventional lecture method. The research instrument used for data collection was the Biology Achievement Test (BAT), developed by the researcher to assess students' understanding of key Biology concepts such as the respiratory system, tissues, and transport mechanisms in animals. Content and face validity of the BAT were ensured through expert review by specialists in science education and educational measurement. The reliability of the instrument was established using test retest, which yielded a coefficient of 0.879, indicating a high level of internal consistency. Data collected were analyzed using descriptive statistics and Analysis of Covariance (ANCOVA). The findings revealed that both PBL and PI significantly enhanced students' academic achievement in Biology when compared to the conventional lecture method. Among the three groups, students exposed to PBL achieved the highest mean gain in the post-test, indicating a stronger impact on conceptual understanding and knowledge retention. The study recommends the integration of PBL strategies into Biology instruction at the senior secondary level to promote meaningful learning and improve science achievement.