Effect of Explicit and Concrete-Representational-Abstract Strategies on Students’ Learning Outcomes in Basic Science

Basic Science serves as a foundational discipline that introduces core scientific concepts and principles, preparing students for advanced studies in Biology, Chemistry, and Physics. Despite its importance, student performance in Basic Science across Nigeria is poor, particularly in Ibarapa, This is largely attributed to teachers’ methods of teaching the subject, which resulted in students' perceived difficult learning outcomes (achievement in and attitude of the students). Previous studies largely looked into student and teacher factors, with less attention paid to active learning strategies such as explicit and concrete-representational-abstract. This study, therefore, was designed to determine to compare the effects of Explicit Strategy (ES) and Concrete-representational-abstract Strategy (CraS) on students’ learning outcomes of some perceived difficult concepts in Basic Science in Ibarapa, Nigeria. It also examined the moderating effects of Self-efficacy and teachers’ Area of Specialisation (Basic, Core Science, and Non-science) The study adopted a pretest-posttest control group quasi-experimental design with a 3x2x3 factorial matrix. Three Local Government Areas in Ibarapa were adopted, and nine Junior School II were randomly selected (three per LGA). The schools were randomly assigned to ES (272), CraS (293), and the control (223) groups. The instruments used were Students’ Achievement Test in BS (r=0.77); Students’ Attitude to BS (r=0.72), Students’ Self-efficacy (r=0.70) questionnaires and guides. The data were analysed using ANCOVA and Bonferoni post-hoc, while the hypotheses were tested at a p ? 0.05 level of significance. The study revealed that The findings affirm that the concrete-representational-abstract strategy is superior in promoting deep learning and retention in both achievement and attitude to Basic Science. However, there was a significant main effect of treatment on students’ attitude (F(2; 787)=7.51; ?2=0.02). The participants exposed to the Concrete-representational-abstract-strategy had the highest post-mean score (83.95), followed by those in the explicit strategy (82.16) and the conventional (79.78) groups. There was a significant main effect of Students’ Self-efficacy on attitude (F(2; 787)=13.35; ?2=0.02) but not on achievement. There were also significant main effects of teachers’ area of specialisation on achievement (F(2; 787)=202.64; ?2=0.35) and attitude (F(2; 787)=62.64; ?2=0.14). Consequently, its effectiveness is amplified when delivered by teachers with a strong background in basic science education. Explicit instruction, while structured and clear, may not foster the same level of engagement or conceptual mastery, particularly when used by educators outside the basic science domain, like core science subjects (Biology, Chemistry, and Physics) or non-science. The study, therefore, will help teachers and learners if the strategies are adopted by basic science teachers to teach any concepts in basic science in the classroom.