Table 12.

Main effects of Montessori education versus traditional education for all nonacademic.

Outcome	Hedges’ g	95% CI of g	df	p	I 2	N of studies	N of effect sizes
All nonacademic outcomes	0.33	0.16, 0.50	16.2	0.001	85.73	18	91
Creativity	0.26	−0.21, 0.74	4.76	0.209	74.49	6	24
Executive function	0.36	0.15, 0.58	9.26	0.004	80.41	11	34
Inner experience of school	0.41	0.19, 0.62	3.92	0.007	66.61	5	10
Social skills	0.23	−0.02, 0.49	7.30	0.070	82.92	9	23

Note: Cluster robust estimates with df < 4.00 should be interpreted with caution (Tanner‐Smith, Tipton, & Polanin, 2016). Positive effect sizes favor Montessori over traditional education.

Abbreviation: CI, confidence interval.

^a A cluster‐robust model was used for all outcomes except social studies, in which a random‐effects model was used. The social studies outcome had effect sizes from only one study.