Table 2. Effect sizes and testing power for between-group comparisons.

		Effect size	Testing power
Pre	PA group -SA group	0.23	0.07
	PA group-NA group	0.28	0.08
	SA group-NA group	0.01	0.03
Post	PA group -SA group	0.64	0.25
	PA group-NA group	0.46	0.13
	SA group-NA group	0.24	0.06
Retention	PA group SA group	1.01	0.52
	PA group-NA group	0.85	0.35
	SA group-NA group	0.30	0.08

AA: active assistance; PA: passive assistance; NA: no assistance.