Factor Structure of the WISC-R

Area of Science:

• Psychometrics
• Developmental Psychology
• Educational Psychology

Background:

• The Wechsler Intelligence Scale for Children-Revised (WISC-R) is a widely used tool for assessing child intelligence.
• Understanding the underlying factor structure of the WISC-R is crucial for accurate interpretation of test results.
• Previous models have proposed different factor structures to explain WISC-R performance.

Purpose of the Study:

• To perform a confirmatory factor analysis on the WISC-R subtests across 11 age groups.
• To compare the fit of single-factor, two-factor, and three-factor models to the WISC-R data.
• To examine the consistency of these factor structures across different age groups and in previously published studies.

Main Methods:

• Simultaneous maximum likelihood confirmatory factor analysis was conducted on the 12 WISC-R subtests.
• Models tested included single-factor, orthogonal and oblique two-factor (Verbal and Performance), and orthogonal and oblique three-factor structures.
• Analyses were replicated on 11 independent samples from published literature.

Main Results:

• The single-factor model provided a reasonable fit, but with some misspecification.
• Oblique multi-factor models demonstrated a better fit than the single-factor model, although they also showed misspecification.
• Factor structures (single-factor, oblique two-factor, oblique three-factor) were consistent across age groups and replicated across diverse populations.

Conclusions:

• The WISC-R primarily comprises a general intellectual factor.
• Existing models explaining WISC-R performance are only partially accurate.
• The factor structure of the WISC-R is robust and consistent across developmental stages and different samples.