Reliabilities of WMS–IV Discrepancy Score Comparisons for Subtests, Indexes, and Selected WAIS–IV Composites

Abstract

This investigation provides internal consistency reliabilities for the Wechsler Memory Scale–Fourth Edition (WMS–IV) subtest and index discrepancy scores using the standardization samples of the Adult and Older Adult batteries. Subtest reliabilities ranged from .00 to .93 for Adults and .25 to .94 for Older Adults. Three of 91 Adult coefficients and three of 24 Older Adult coefficients reached the recommended level (≥ .90). Index reliabilities ranged from .46 to .94 for 100 Adult Battery comparisons and .19 to 93 for 36 Older Adult Battery comparisons. Each battery had 10 coefficients ≥ .90. Ability–memory discrepancies were reported using WAIS–IV VCI, PRI, WMI, and GAI as intelligence standards. Ability–memory comparisons for the Adult Battery ranged from .82 to .93 with 12 of 20 comparisons ≥ .90; Older Adult Battery reliabilities ranged from .85 to .94 with six of 16 comparisons ≥ .90. In terms of discrepancy score reliabilities, the WMS–IV represents a marked improvement over the WMS–III.