Structural Validity of the WISC-IV for Students With Learning Disabilities

Area of Science:

• Psychometrics
• Educational Psychology
• Neuropsychology

Background:

• The Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) is a widely used measure of cognitive ability in children.
• Assessing the structural validity of the WISC-IV is crucial for accurate interpretation, particularly in clinical populations.
• Students with specific learning disabilities (SLD) often present with complex cognitive profiles requiring careful assessment.

Purpose of the Study:

• To evaluate the structural validity of the WISC-IV using confirmatory factor analysis.
• To determine the best fitting factor model for the WISC-IV in a clinical sample of students with SLD.
• To inform score interpretation guidelines for the WISC-IV in this population.

Main Methods:

• Confirmatory factor analysis (CFA) was employed.
• A clinical sample of 1,537 students diagnosed with SLD was utilized.
• Data were collected from two large southwestern school districts.

Main Results:

• A bifactor model, comprising four domain-specific factors and one general intelligence factor, demonstrated the best fit to the data.
• The general intelligence factor accounted for a substantial portion (48%) of the common variance.
• The structural validity of the WISC-IV for students with SLD was supported.

Conclusions:

• The WISC-IV's structure is valid for assessing students with SLD.
• Interpretation of WISC-IV scores should prioritize the Full-Scale IQ.
• The contribution of domain-specific factors is marginal when controlling for the general intelligence factor.