Factor Structure of the WISC-III for Students with Learning Disabilities

Abstract

The factor structure of the WISC-R for both regular and special education populations has been well documented. Published data also have indicated that the factor structure of the WISC-R is similar across special education populations. However, with the development of the WISC-III, comparable information is not yet well established. With the addition of a new subtest, and a hypothesized new fourth factor, additional data with regard to the psychometric properties of the WISC-III are required. This study examined the factor structure of the WISC-III, using an oblique method of rotation, in a sample of students with learning disabilities. Results provide support for the construct validity of the Verbal and Performance factors, but empirical support was less evident for the use of the other factor scores, Freedom from Distractability and Processing Speed. Implications for school psychologists are presented, and directions for future research are provided.