Construct bias in the differential ability scales? Confirmatory and hierarchical factor structure across three ethnic groups

The Differential Ability Scales (DAS) is a relatively new and well-received measure of intelligence for children and youth ages 2 1/2 through 17. Although there is evidence to support the construct validity of the DAS, there is little evidence concerning construct bias in the DAS. The purpose of this research was to test for construct bias in the DAS for children from the three major ethnic groups, and across the entire age range of the DAS. We also sought to determine the nature of the constructs measured across these three groups. Both purposes were accomplished through hierarchical, multisample confirmatory factor analysis of DAS standardization data. The research also illustrates the use of this methodology to perform a comprehensive test of construct bias. Results suggest that the DAS measures the same constructs for all three ethnic groups across the four age levels studied; the DAS, therefore, shows no construct bias across groups. Furthermore, the hierarchical factor structure of the test is quite consistent with the DAS's actual structure, thus supporting the construct validity of the DAS. The DAS's Nonverbal reasoning cluster may be a good measure of fluid intelligence.