Project-based learning in schools: a multi-complementary study of its effectiveness

Abstract

This mixed-methods research evaluates the effectiveness of Project-Based Learning (PBL) practices using a comprehensive Multi-Complementary (McA) research approach. This assessment involves three main stages: (i) pre-complementary knowledge phase, including a meta-analysis and meta-thematic analysis; (ii) post-complementary knowledge phase, involving a pre-test and post-test control group experimental design; and (iii) complementary phase, synthesizing the previous findings for deeper insights into the effectiveness of PBL practices. The findings revealed that PBL has a significant positive impact on academic achievement based on Hedges’ g value effect size of 1.11. The experimental implementation of PBL in mathematics instruction also yielded a moderate effect (g = 0.66). Thematic analysis highlighted positive effects on scientific process skills and social competencies while also identifying practical limitations in PBL implementation. These results suggest that PBL can significantly enhance learning outcomes when supported by appropriate planning and teacher guidance. The comprehensive outcomes of this study are expected to inform PBL implementation in classrooms and support more effective and efficient use of this approach.