Factorial equivalence of the Wechsler Memory Scale: revised across standardization and clinical samples

A two-phased analysis of the WMS-R is reported In the first phase, confirmatory factor analyses of the WMS-R standardization sample were conducted in order to identify a baseline model against which to compare two large samples of substance abusers These analyses revealed that most of the exploratory factor models reported in the literature were plausible representations of the WMS-R, however, a three-factor oblique model representing Attention/Concentration, Verbal Memory, and Visual Memory emerged as the best fitting model In the second phase, we conducted multi-sample factor analyses to test the generality of this model in two large samples of inpatients at an addiction recovery unit The results revealed that the factor loadings, subtest error variances (reliabilities), factor variances, and factor covariances were identical across groups Thus the factor structure of the WMS-R appears to be unaltered in these clinical groups Researchers may thus make meaningful comparisons of the dimensions indexed by the WMS-R between normal samples and neuropsychological groups with diffuse pathology.