Table 3.

Group Differences in Rate of Total Acts and Gestures, and Proportion of Acts and Gestures for Each Communicative Function/Category

								Pairwise group differences
	ASD (n = 50)		DD (n = 25)		TD (n = 50)			DD-ASD		TD-ASD
Measure	M	SD	M	SD	M	SD	F value	p value	Effect sized	p value	Effect sized
Rate of Total Acts	1.23a	0.83	1.81b	0.83	2.40c	0.78	26.17***	.019	0.70	.000	1.45
Functions (%)
Behavior Regulation	65.16a	22.12	52.80ab	19.81	49.62b	18.26	7.92**	.052	−0.59	.001	−0.77
Social Interaction	19.71a	20.39	13.19ab	16.13	11.51b	9.90	3.24*	.354	−0.36	.037	−0.54
Joint Attention	15.12a	15.13	34.01b	19.89	38.86b	17.56	25.67***	.000	1.08	.000	1.45
Rate of Total Gestures	1.16a	0.77	1.73b	0.85	2.09b	0.75	17.99***	.021	0.70	.000	1.22
Proportion of Gestures (%)
Deictic	66.10a	25.46	84.36b	12.22	83.44b	11.85	10.39***	.000	0.97	.000	0.93
Representational	8.92a	16.43	8.71a	10.18	12.34a	10.51	1.06	1.000	−0.02	.519	0.25
Contact without objects	24.98a	25.43	6.93b	9.24	4.22b	8.20	15.00***	.000	−1.04	.000	−1.23

Note: Means in the same row with different subscripts differ significantly at p <.05. Rate reflects number of acts/gestures per minute.

Proportion is the number of acts/gestures for each function/category divided by the total number of acts/gestures.

Degrees of freedom are Welch corrected when necessary for violation of homogeneity of variance as assessed by Levene’s test.

^dEffect size based on Cohen’s d = .20 is small, .50 is medium, and .80 is large

^*p <.05

^**p <.01

^***p <.001