A Meta-Analysis Review of the Effects of Project-BasedLearning on Critical Thinking in Educational Systems

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Talebı Ghahremanlouy Olya Z.

Journal of Research in Educational Systems, cilt.20, sa.72, ss.80-95, 2026 (Hakemli Dergi)

Özet

Objective: This study aimed to determine the overall effect size of project-basedlearning (PBL) on the development of critical thinking and to examine its effectivenessacross different educational levels through a systematic meta-analytic approach.Method: The present research employed a quantitative meta-analysis conducted inaccordance with the PRISMA guidelines. A total of 17 experimental and quasi-experimental studies published between 2019 and 2025 were selected based onpredefined inclusion and exclusion criteria. The pooled effect size was calculated usingHedges’s g under a random-effects model (REML). Study heterogeneity was assessedusing the Q statistic and the I² index, and subgroup analyses were performed based oneducational level Publication bias was examined using Egger’s and Begg’s tests as wellas the trim-and-fill method.Results: The results indicated that project-based learning had a positive and statisticallysignificant effect on critical thinking (g = 0.92, 95% CI: 0.83 to 1.01), representing amoderate-to-large effect size. Overall heterogeneity was low and non-significant (I² =0%), although substantial heterogeneity was observed in certain subgroups, particularlyat the university level. Subgroup analyses revealed variations in effect sizes acrosseducational levels; however, these differences were not statistically significant. Testsfor publication bias provided no conclusive evidence of serious bias, and the trim-and-fill analysis did not alter the overall effect size.Conclusions: The findings support project-based learning as an effective, evidence-based instructional approach for enhancing critical thinking within educational systems.Nevertheless, given the limited number of eligible studies and variations inconceptualization and contextual factors, the generalizability of the results should beinterpreted with caution. Further high-quality experimental research across diverseeducational and cultural contexts is recommended Objective: This study aimed to determine the overall effect size of project-basedlearning (PBL) on the development of critical thinking and to examine its effectivenessacross different educational levels through a systematic meta-analytic approach.Method: The present research employed a quantitative meta-analysis conducted inaccordance with the PRISMA guidelines. A total of 17 experimental and quasi-experimental studies published between 2019 and 2025 were selected based onpredefined inclusion and exclusion criteria. The pooled effect size was calculated usingHedges’s g under a random-effects model (REML). Study heterogeneity was assessedusing the Q statistic and the I² index, and subgroup analyses were performed based oneducational level Publication bias was examined using Egger’s and Begg’s tests as wellas the trim-and-fill method.Results: The results indicated that project-based learning had a positive and statisticallysignificant effect on critical thinking (g = 0.92, 95% CI: 0.83 to 1.01), representing amoderate-to-large effect size. Overall heterogeneity was low and non-significant (I² =0%), although substantial heterogeneity was observed in certain subgroups, particularlyat the university level. Subgroup analyses revealed variations in effect sizes acrosseducational levels; however, these differences were not statistically significant. Testsfor publication bias provided no conclusive evidence of serious bias, and the trim-and-fill analysis did not alter the overall effect size.Conclusions: The findings support project-based learning as an effective, evidence-based instructional approach for enhancing critical thinking within educational systems.Nevertheless, given the limited number of eligible studies and variations inconceptualization and contextual factors, the generalizability of the results should beinterpreted with caution. Further high-quality experimental research across diverseeducational and cultural contexts is recommended