Table 1.

Observed means for outcome measures over time by group with effect sizes

Variable	Pretest (n = 404) M (SD)	Post-test (n = 364) M (SD)	M Δa	d	Follow-up (n = 403) M (SD)	M Δb	d
Paying attention
MS	2.63 (1.0)	2.95 (.9)	+.32**	.42	2.91 (.9)	+.28**	.37
MS+	2.64 (1.0)	2.89 (.9)	+.25**	.33	3.01 (.9)	+.37**	.46
Between group difference			.07	.09		.09	.09
Self-control
MS	2.79 (1.0)	3.13 (.9)	+.34**	.43	3.07 (1.0)	+.28**	.32
MS+	2.96 (1.0)	3.28 (.8)	+.32**	.42	3.30 (.8)	+.34**	.43
Between group difference			.02	.01		.06	.11
Participation
MS	3.03 (.9)	3.31 (.9)	+.28**	.37	3.25 (.8)	+.22**	.28
MS+	3.00 (.9)	3.34 (.9)	+.34**	.45	3.31 (.8)	+.31**	.39
Between group difference			.06	.08		.09	.11
Respect for others
MS	2.96 (1.0)	3.16 (1.0)	+.20*	.25	3.18 (.9)	+.22**	.26
MS+	3.11 (.9)	3.35 (.9)	+.24**	.33	3.37 (.8)	+.26**	.35
Between group difference			.04	.08		.04	.09
Sum score
MS	11.40 (3.2)	12.54 (3.1)	+1.14**	.50	12.42 (3.0)	+1.02**	.43
MS+	11.70 (3.1)	12.86 (3.0)	+1.16**	.52	12.96 (2.8)	+1.26**	.55
Between group difference			.02	.02		.24	.12

^**p < .01,

^*p < .05—significance for paired sample t test for within-subjects repeated measures

^aM Δ = mean difference between baseline and immediate post-test score;

^bM Δ = mean difference between baseline and follow-up score; d = Cohen’s d corrected for within-subjects dependence between means; MS = Mindful Schools; MS+ = Mindful Schools + added sessions