. Author manuscript; available in PMC: 2012 Jul 1.

Published in final edited form as: Child Neuropsychol. 2011 Jul;17(4):347–367. doi: 10.1080/09297049.2010.544647

Table 4.

Means, Standard Deviations, and the Results of Independent Samples t-Test Analysis on Cognitive and Achievement Scores for Liberal and Restrictive Groups.

	Liberal (n = 33)		Restrictive (n = 23)		t	d.f.	p-value	Effect Size
	Mean	SD	Mean	SD	t	d.f.	p-value	Effect Size
GAI	93.21	20.7	103.61	15.7	2.036	54	.047	.267
VCI	93.85	26.0	104.78	15.7	1.798	54	.078	.238
PRI	91.67	18.1	99.70	15.5	1.729	54	.089	.229
PSI	88.82	14.4	95.5	14.8	1.694	54	.096	.225
WRAT-III	93.94	15.0	105.83	10.2	3.300	54	.002	.410

Note. General Ability Index (GAI), Verbal Comprehension Index (VCI), Perceptual Reasoning Index (PRI), Processing Speed Index (PSI), Wide Range Achievement Test, Third Edition (WRAT-III). Effect sizes (r) were calculated by r = √(t²/(t²+df)).