Wechsler Memory Scale –3rd Edition (WMS-III)

Purpose: Designed to assess learning, memory, and working memory.

Population: Individuals in the age range of 16-89 years.

Score: Eight primary indexes and four supplemental auditory process composites.

Time:  (30 - 35) minutes, 25-30 min. between tests, (15-20) min. for optional subtests.

Author: David Wechsler.

Publisher: The Psychological Corporation.

Description: This third edition updates the WMS-R and provides subtest and composite scores that assess memory and attention functions using both auditory and visual stimuli.  There are now eight Primary Indexes (Auditory Immediate (was Verbal), Visual Immediate (was Visual), Immediate Memory (new), Auditory Delayed (new), Visual Delayed (new), Auditory Reception Delayed (new), General Memory (only delayed subtest scores), and Working Memory), which constitute Immediate Memory, General (Delayed) Memory, and Working Memory (was Attention/Concentration).  This edition retains the index score configuration of the WMS-R, but scale content, administration and scoring procedures have been changed.  There is one slight change to the optional Information and Orientation subtest and one item has been deleted and six items added to the Mental Control subtest. The Figural Memory, Visual Paired Associated, and card B of Visual Reproduction subtests have been dropped.  There are slight wording and administration changes in Logical Memory, and added subtests help to assess various aspects of visual memory.  Requires strict and discreet timing for certain subtests.

Scoring: Requires verbatim recording of responses for subjective scoring on many sub-tests.

Reliability: The reliability coefficients for the WMS-III Primary subtests and Primary Indexes were on average found to be higher than for the WMS-R.  Internal consistency reliability coefficients ranged for .70s to the .90s.

Validity: Correlation with the WMS-R was not direct because of the many changes in the scales.  The Verbal Memory of the WMS-R had a .72 correlation coefficient with the Auditory Immediate, .68 with the Auditory Delayed, and .65 with General Memory of the WMS-III.  The General Memory of the WMS-R and the Auditory Immediate  .73, Auditory Delay .69, and general memory .67 of the WMS-III.  As expected the correlations were lower for visually presented material with .34 for verbal memory and visual memory indexes.  When correlated with the Children’s Memory Scale, the WMS-III auditory indexes correlated highest with the corresponding CMS indexes. Studies comparing the WMS-III and the WIAT show highest correlations between the WMS-III auditory indexes and working memory indexes and the WIAT subtests and composites, similar to results found with the CMS and the WIAT.  In comparing the WMS-III with the WAIS-III there is a pattern of the auditory memory correlating more strongly with the VIQ and the visual memory measures correlating more strongly with the PIQ as an indication of convergent and divergent validity; while they are related, they measure different constructs.

Norms: The normative sample for the WMS-R included six age groups of 50 subjects each for a total sample of 300 aged 16 to 74 years. In contrast the WMS-III standardization sample, stratified to be representative of the general population included 1250 individuals aged 16-89 years.

Suggested use:  The WMS-III provides a more detailed analysis of memory function.  When used in conjunction with the WAIS-III, meaningful comparisons between intellectual ability and memory functions can be made.