Development of a new Delayed Memory Index for the WMS-III

Area of Science:

• Neuroscience
• Psychology
• Psychometrics

Background:

• The Weschler Memory Scale-Third Edition (WMS-III) Immediate Memory Index (IMI) and General Memory Index (GMI) lack parallel structure.
• This structural difference complicates direct comparisons between immediate and delayed memory scores.
• The GMI's inclusion of the Auditory Recognition Delayed subtest is problematic due to skewness and ceiling effects.

Purpose of the Study:

• To introduce the Delayed Memory Index (DMI) as a more structurally parallel alternative to the WMS-III GMI.
• To address the limitations of the current WMS-III memory indices for comparative analysis.
• To provide normative data and initial psychometric property estimates for the DMI.

Main Methods:

• Development of a new index score, the Delayed Memory Index (DMI), excluding the Auditory Recognition Delayed subtest.
• Construction of normative tables for the DMI, incorporating either the Faces or Visual Reproduction subtest.
• Description of initial estimates of the DMI's psychometric properties.

Main Results:

• The DMI offers a more parallel structure compared to the WMS-III GMI.
• Normative data are presented for the DMI using two variations (with Faces or Visual Reproduction subtest).
• Initial psychometric properties of the DMI have been estimated.

Conclusions:

• The proposed Delayed Memory Index (DMI) provides a viable alternative for assessing delayed memory within the WMS-III framework.
• The DMI's more parallel structure facilitates clearer comparisons between immediate and delayed memory performance.
• The DMI offers improved psychometric characteristics over the existing GMI.