Factor Structure, Internal Consistency, and Screening Sensitivity of the GARS-2 in a Developmental Disabilities Sample

Table 3

Internal consistency estimates for factor-based scales and GARS-2 subscales.

Factor/subscale	Cronbach’s alpha	Ordinal alpha	Number of items
Factor I	.92	.95	18
Factor II	.92	.94	16
Factor III	.84	.89	8
Stereotyped Behavior	.90	.94	14
Communication	.89	.92	14
Social Interaction	.89	.92	14

Note. Cronbach’s and ordinal alpha coefficients are estimated using the SPSS R menu [17]. Ordinal alpha is calculated using polychoric correlation coefficients in the alpha formula [18].