Is all that glitters gold? Meta-analytical Systematic Review of the Effect of the Montessori

In this pre-registered review, we analyzed 198 studies to assess the effectiveness of the Montes-sori method in educational contexts. Our findings indicated a generally positive effect of the Montessori method, particularly in Pretest-Posttest and Posttest designs. However, the analyses revealed considerable publication bias and methodological shortcomings across the reviewed studies. Issues such as limited transparency, inadequate adherence to Montessori principles, and inconsistent reporting of intervention fidelity undermined the robustness of the findings. Moder-ation analyses revealed that sample type and intervention agent influenced effect variability. Our evaluation of methodological quality highlighted critical deficiencies in experimental con-trol and replicability. Our approach provided a more reliable evaluation of the Montessori method’s impact while setting a high standard for future research. The results underscored the need for improved methodological rigor and transparency in educational research to ensure more accurate and generalizable conclusions