Abstract
Dimensional structures underlying the Wechsler Memory Scale–Fourth Edition (WMS–IV) and Wechsler Memory Scale–Third Edition (WMS–III) were compared to determine whether the revised measure has a more coherent and clinically relevant factor structure. Principal component analyses were conducted in normative samples reported in the respective technical manuals. Empirically supported procedures guided retention of dimensions. An invariant two-dimensional WMS–IV structure reflecting constructs of auditory learning/memory and visual attention/memory (C1 = .97; C2 = .96) is more theoretically coherent than the replicable, heterogeneous WMS–III dimension (C1 = .97). This research suggests that the WMS–IV may have greater utility in identifying lateralized memory dysfunction.
Notes
1The Cattell–Horn–Carroll cognitive abilities model does differentiate between broad constructs of “long-term storage and retrieval” and “short-term memory,” though the latter construct is more consistent with the notion of working memory or attention in neuropsychology (CitationMcGrew, 1997).
2WMS–IV and WMS–III oblique and orthogonal solutions were largely consistent. Orthogonal solutions can be obtained from J. Hoelzle upon request.
3Inconsistent solutions may be obtained by contacting J. Hoelzle.
4Congruency coefficients did not meaningfully improve when the Auditory Recognition Delayed score was excluded from analyses.