Redefining the factor structure of the Wechsler Memory Scale-III: confirmatory factor analysis with cross-validation.

The purpose of this study was to revisit the underlying factor structure of the Wechsler Memory Scale-III. The WMS-III Technical Manual (Wechsler, 1997) presented findings from confirmatory factor analyses that support a three- and five-factor solution with separate immediate and delayed memory factors. A rigorous structural equation modeling approach was used to examine the factor structure of the test. The results verify that a three-factor model composed of verbal (immediate and delayed), visual (immediate and delayed), and working memory factors accurately represents the factor structure of the WMS-III. Results were cross-validated on an independent sample.