Confirmatory and Hierarchical Confirmatory Analysis of the Differential Ability Scales

The purposes of this research were, first, to determine whether the varied tests contained in the Differential Ability Scales (DAS) measure the same constructs across its wide range, and, second, to determine what constructs and abilities are being measured by this new test. Confirmatory analysis was performed on the standardization data of the DAS using the LISREL 7 computer program. The first set of analyses, which included statistical comparisons of covariance matrices and first-order confirmatory factor analyses, suggested that the constructs measured by the DAS are quite consistent across overlapping age ranges. The second set — hierarchical confirmatory factor analyses — suggested that the DAS first provides a good measure of g, general intelligence. Also, the DAS appears to measure verbal ability and nonverbal reasoning skills.