摘要：Nigerian students have not been performing up to expectation in public chemistry examinations. One of the causes identified as being responsible for this is the teachers’ use of inappropriate instructional strategies. This study was conducted to determine the effects of mastery learning instructional strategy on secondary school students’ achievement in mole concept, a topic that has been empirically identified as contributing to the poor performance of candidates in School Certificate Chemistry. The study used a quasi-experimental design and followed the non-randomized, non-equivalent pre-test and post-test group design. Data were obtained from two intact classes in two purposively selected secondary schools in Ilorin South Local Government Area of Kwara State, Nigeria. The experimental group was taught the mole concept using mastery learning instructional strategy while the control group was taught using the conventional teaching method. The data obtained were analyzed using t-test and Analysis of Covariance (ANCOVA) with the pre-test and post-test scores as covariates. It was found that students taught using the mastery learning instructional strategy performed better (mean score 15.50) than their counterparts in the control group (mean score 7.04). Furthermore, gender had no significant effect on the achievement of the students taught using the mastery learning instructional strategy. Results also showed a statistically significant covariance between scoring level and group. Based on the findings of this study, it is recommended that teachers should consider using mastery learning instructional strategy for chemistry instruction to improve the performance of their students in chemistry examinations.
关键词：Mastery learning;senior school students;achievement;mole concept
