Montessori primary schools' effectiveness: a quasi-experimental study on schooling outcomes

Montessori education advocates individualized student development, moving away from standardized schooling outcomes. This study investigates whether a group of Montessori students (experimental groups) exhibit more diverse learning achievements compared to a control group of non-Montessori students, matched through the simple matching method (Bailey, 2007), to control for background variables. Employing a quasi-experimental design, the hypothesis tested was that the experimental groups (N = 535-710) would display a significantly higher standard deviation in standardized measures of schooling outcomes in mathematics and language. The study encompassed 2nd, 5th, 8th, and 10th grade students across two separate cohorts. Results indicate that, depending on grade and cohort, Montessori students attain either comparable or significantly higher scores than non-Montessori students, with greater score variability observed, particularly in mathematics. This finding implies the necessity for future investigations into Montessori teachers' instructional practices in mathematics and language.