Table 2.

Study 1: comparison of ABAS-2 and ABAS-3 standardised scores; mean (SD) (n = 2327)

	ABAS-2 cohort (n = 1036)	ABAS-3 cohort (n = 1291)	t value†	P value	Cohen’s d	95% CI [lower, upper]
WISC-4/5 VCI ABAS composites	93.67 (16.95)	93.08 (17.42)	0.82	0.41	0.03	[−0.82, 2.00]
GAC (SS)	77.65 (16.46)	83.02 (12.21)	9.04	<0.001	0.37	[4.21, 6.54]
Conceptual (SS)	79.92 (14.71)	82.61 (12.27)	4.81	<0.001	0.20	[1.60, 3.79]
Social (SS)	85.21 (16.89)	85.88 (13.68)	1.05	0.29	0.04	[0.58, 1.91]
Practical (SS)	77.90 (18.16)	85.12 (12.71)	11.25	<0.001	0.47	[5.96, 8.47]

Note. ABAS, Adaptive Behavior Assessment System; CI, confidence interval; SD, standard deviation; SS, standard score; VCI, Verbal Comprehension Index; WISC, Wechsler Intelligence Scales for Children.

^†Degrees of freedom = 2325 for all t tests.