The hierarchical factor structure of the WAIS-R for learning-disabled adults

A hierarchical factor solution was obtained on intercorrelations among the WAIS-R subtests for a sample of 232 learning-disabled adults. An ability arrangement in agreement with Vernon's structural paradigm was obtained. The ability hierarchy included a relatively weak general intelligence (g) factor defined by positive loadings from all WAIS-R subtests. The primary level of the hierarchy included spatial-perceptual-mechanical (k:m), verbal comprehension (VC) and freedom-from-distractibility (FD) factors. Thus, the factor structure found with learning-disabled adults on the WAIS-R is similar to the factor structure found with learning-disabled children on the WISC-R. This suggests that it may be possible to generalize from the many hierarchical studies that have been done on the WISC and WISC-R and apply the composite hierarchical factor structure that Blaha and Wallbrown (1984) derived from these studies to the WAIS-R.