The impact of project-based learning on developing scientific inquiry skills in seventh-grade chemistry students in Central Province schools, Sri Lanka

Abstract

Traditional teacher-centred approaches to science education have been widely criticised for their limited effectiveness in fostering essential skills such as critical thinking and problem-solving. Within the context of the Sri Lankan educational system, specifically in the Central Province, this study addresses the need for a shift towards more student-centred pedagogies. The research examines the impact of Project-Based Learning (PBL) on the development of scientific inquiry skills in Grade 7 chemistry students, comparing its effectiveness with traditional teaching methods. A quasi-experimental, mixed-methods design was implemented with 169 Grade 7 students from two Central Province schools, each with parallel classes (School A: 71; School B: 68). Two units from the Grade 7 science (chemistry units) were selected for the study. A pre-test confirmed equivalence between parallel classes. All lessons in each school were taught by the same teacher to maintain consistency, and for PBL, lesson plans were prepared by the researcher with the methodology explained in advance. In the first unit, Grade 7A was taught through PBL and Grade 7B through traditional methods; in the second unit, the methods were vice versa. The same way was followed in both schools. Students’ achievement, skills, and perceptions were measured through tests, scoring rubrics, and interviews. Quantitative analysis indicated a statistically significant improvement in the scientific inquiry skills of the experimental group (p < .05), with a mean post-test score of 82.5 (SD = 8.1) compared to 65.2 (SD = 9.5) for the control group. Qualitative findings revealed that students exposed to PBL demonstrated higher engagement, improved collaboration, and a deeper understanding of chemistry concepts. Teachers also expressed positive attitudes toward PBL, highlighting its potential to promote student autonomy and practical application of knowledge, despite challenges in implementation and time management. Overall, the findings suggest that project-based learning is a more effective pedagogical approach than traditional methods for enhancing scientific inquiry skills in Grade 7 chemistry education. It is recommended that Sri Lankan educational policymakers and curriculum developers integrate PBL into the national curriculum to equip students with the competencies required for the 21st century.