Table 2.

Required sample size to achieve a statistical power of 1−β = .8 given α = .05 and the effect size ${\eta }_p^2$ or ${\omega }_p^2$ in RM-ANOVA for effects with one numerator degree of freedom

	${\eta }_p^2/{\omega }_p^2$
${\eta }_p^2/{\omega }_p^2$	.00	.01	.02	.03	.04	.05	.06	.07	.08	.09
0.0		779	387	256	191	152	125	107	93	82
0.1	73	66	60	55	51	47	44	41	38	36
0.2	34	32	30	29	27	26	25	24	23	22
0.3	21	20	19	18	18	17	16	16	15	15
0.4	14	14	13	13	13	12	12	11	11	11
0.5	10	10	10	10	9	9	9	9	8	8
0.6	8	8	7	7	7	7	7	7	6	6
0.7	6	6	6	6	5	5	5	5	5	5

Row names indicate the first decimal place of ${\eta }_p^2/{\omega }_p^2$, column names indicate the second decimal place. For instance, N = 26 subjects are required to achieve a power of 1−β = .8 for an effect size of ${\eta }_p^2/{\omega }_p^2=.25$ (third row, sixth column)