Confirmatory factor analytic models of the WAIS-R for neuropsychiatric patients

Abstract

Five multifactor models, in both orthogonal and oblique versions, and a single‐factor model of the WAIS‐R's factor pattern were examined by confirmatory maximum likelihood factor analyses of a data matrix constructed from the results for 90 neuropsychiatric patients. None of the models fits the data matrix in an absolute sense, even though all of the models represented an improvement over a null statistical model. For the multifactor models, the best results were obtained by oblique solutions, in which the degree of correlation between the factors varied from 0.71 to 0.93. The single‐factor model fit nearly as well as, and in some instances better than, many of the multifactor models. The best‐fitting model, viz., a three‐factor oblique one, was only marginally better in its fit than two of the three two‐factor models or the competing three‐factor model.

Structure of the Wechsler Adult Intelligence Scale – Revised in the Italian Normal Standardisation Sample

“…Confirmatory factor analytic studies conducted using the WAIS-R yielded three different solutions: one-factor model in which all 11 subtests of the WAIS-R were allowed to load on a general factor (Fowler, Zillmer, & Macciocchi, 1990;O'Grady, 1983); two-factors model that reflects the structure of the WAIS-R as embodied in Wechsler's (1981) theory of the instrument, that is a Verbal and Performance factor (Plake et al, 1987); and three-factors model as Verbal Comprehension, Perceptual Organisation, and Memory/Freedom From Distractibility (Davis et al, 2003;Waller & Waldman, 1990). From Davis et al (2003) the results favoured the threefactors model in which Digit Symbol loads on Perceptual Organisation rather than on attentional factor (commonly named Freedom From Distractibility).…”