The Factor Structure of the WAIS-R: Replicability Across Age-Groups.

Area of Science:

• Psychometrics
• Cognitive Psychology

Background:

• The Wechsler Adult Intelligence Scale-Revised (WAIS-R) is a widely used measure of adult intelligence.
• Established factor models for the WAIS-R include a one-factor (General Intelligence, g) and a two-factor (Verbal and Performance) structure.
• A three-factor model (Verbal Comprehension, Perceptual Organization, Freedom from Distractibility) lacks consistent empirical support across different age groups.

Purpose of the Study:

• To examine the factor structure of the Wechsler Adult Intelligence Scale-Revised (WAIS-R) across nine age groups.
• To compare the consistency of one-, two-, and three-factor models of the WAIS-R across different age cohorts.
• To evaluate the utility of Reliable Component Analysis (RCA) in identifying stable intelligence factors.

Main Methods:

• Factor analysis, including Reliable Component Analysis (RCA).
• Analysis of the WAIS-R across nine distinct age groups.
• Comparison of different factor extraction methods to assess model stability.

Main Results:

• The one-factor (g) and two-factor (Verbal and Performance) models of the WAIS-R demonstrated consistency across age groups, though with some variations.
• The three-factor model, particularly the "Freedom from Distractibility" factor, was not consistently identified across age groups by any method.
• Reliable Component Analysis (RCA) showed strong performance in identifying stable factors across age groups, offering unique insights.

Conclusions:

• The general intelligence and verbal/performance dimensions of the WAIS-R appear robust across adult age ranges.
• The three-factor structure, especially "Freedom from Distractibility," presents interpretational challenges due to its inconsistency across age groups.
• Reliable Component Analysis (RCA) is a valuable method for assessing the stability of psychometric factors across populations and can yield reliable components.