Efficacy of Constructivist Teaching Approaches on Science Achievement and Retention Among Secondary School Students in Enugu State: A Comparative Study

This study investigated the efficacy of constructivist teaching approaches on science achievement and knowledge retention among secondary school students in Enugu State, Nigeria. Despite considerable theoretical advocacy for constructivism in science education, empirical studies comparing its sustained effects with traditional methods in the Nigerian South East context are limited. A quasi-experimental pretest, posttest, and delayed posttest design was employed. Eight intact SS2 classes from eight government secondary schools in Enugu North, Igbo-Eze South, and Oji River Local Government Areas participated. Four classes received constructivist instruction, including problem-posing tasks, group investigation, and reflective journalling, while four classes received conventional instruction over 10 weeks. A validated Science Achievement and Retention Test with a reliability of 0.85 was administered at three intervals. Multivariate Analysis of Covariance and growth curve modelling were used for analysis. Results showed that constructivist classes outperformed conventional classes at both posttest and delayed posttest stages, with the retention gap widening over time. Effect sizes indicated medium to large practical significance. Moderation analysis revealed that students with higher metacognitive awareness benefited most from constructivist instruction. The study contributes to the scarce longitudinal evidence base on constructivism in Nigerian science education and recommends structured constructivist professional development for secondary Science teachers in Enugu State. Keywords: constructivism, science achievement, knowledge retention, secondary students, Enugu State.