Confirmatory factor analysis of the Wechsler Memory Scale-III.

The latent structure of the Wechsler Memory Scale-III was analyzed by confirmatory factor analysis using the covariance matrix based on the 11 primary subtests from the standardization sample. Omnibus fit indexes and individual parameter estimates were examined. Of the five models evaluated, a three-factor model (working memory, auditory memory, and visual memory) provided the best fit for the standardization sample (NNFI = .98, RMSEA = .05, GFI = .98, BIC = 429.42). Models that proposed separate immediate and delayed memory constructs were hampered by inadmissible parameter estimates that signaled model specification errors. R2 values for the Faces subtests were uniformly low for all five models that suggested that this subtest has insufficient commonality with the visual memory construct.