Factor structure of the Differential Ability Scales-Second Edition: Exploratory and hierarchical factor analyses with the core subtests.

Abstract

The present study examined the factor structure of the Differential Ability Scales-Second Edition (DAS-II; Elliott, 2007a) standardization sample using exploratory factor analyses, multiple factor extraction criteria, and hierarchical exploratory factor analyses (Schmid & Leiman, 1957) not included in the DAS-II Introductory and Technical Handbook (Elliott, 2007b). Exploratory factor analyses with multiple factor extraction criteria and hierarchical analyses with the Schmid and Leiman (1957) procedure were conducted with the 3 DAS-II standardization samples (Lower Early Years [Ages 2:6-3:5], Upper Early Years [Ages 3:6-6:11], School-Age [Ages 7:0-17:11]). All factor extraction criteria suggested 1 factor despite the author and publisher recommended and promoted 2 (Ages 2:6-3:5) or 3 (Ages 3:6-6:11, Ages 7:0-17:11) factors. Results indicated that most DAS-II subtests were properly associated with the theoretically proposed first-order factors. Hierarchical exploratory analyses with the Schmid and Leiman procedure, however, found that the hierarchical g factor accounted for large portions of total and common variance, while the 2 or 3 first-order factors accounted for small portions of total and common variance. It was concluded that the DAS-II provides strong measurement of general intelligence but clinical interpretation should be primarily at that level. (PsycINFO Database Record