Table 1.

Statistical Summary Table: Effects of Intervention Group and Time on Mental Rotation

Parameter	Reaction time					Rotation rate
	Estimate	SE	df	P	Effect	Estimate	SE	df	P	Effect
Intercept	−2.67	1.53	53.80	0.09		1.77	1.44	53.49	0.22
Main effects
Time
Post-test—baseline	0.09	0.13	102.51	0.46	0.14	−0.07	0.15	102.12	0.66	−0.13
Follow-up—baseline	−0.12	0.13	103.12	0.37	−0.17	−0.22	0.15	102.98	0.15	−0.44
Group
Training—control	−0.04	0.27	103.98	0.87	−0.06	0.39	0.27	125.35	0.16	0.77
CT—InSight	0.51	0.32	102.50	0.11	0.76	−0.43	0.32	123.64	0.18	−0.87
Time × group interactions
(Post-test – baseline) × (training – control)	0.11	0.27	102.38	0.67	0.17	−0.06	0.31	101.94	0.85	−0.12
(Post-test – baseline) × (CT – InSight)	−0.54	0.32	102.63	0.09	−0.81	0.84	0.37	102.28	0.02	1.68
(Follow-up – baseline) × (training – control)	0.08	0.27	102.70	0.77	0.12	−0.69	0.32	102.38	0.03	−1.40
(Follow-up – baseline) × (CT – InSight)	−0.29	0.32	103.51	0.36	−0.44	−0.05	0.37	103.53	0.89	−0.11

Main effect of group is decomposed into two planned orthogonal contrasts, following Helmert coding, the first comparing the average of the two intervention groups with the control group, the second comparing the two intervention groups with one another. Interaction estimates address whether the group contrasts evinced differential change from baseline to post-test or from baseline to follow-up. Estimate represents the unstandardized regression weight. Effect represents the standardized net effect, which was computed as the value of each contrast (“estimate”) divided by the pooled baseline standard deviation. All effects were adjusted for the covariates of age, education, and gender.

CT, Crazy Taxi; SE, standard error.