Analysis of the Wechsler Adult Intelligence Scale, Third Edition With a Learning Disabled Sample

Until 1981, the Wechsler Adult Intelligence Scale-Revised was the most widely used intelligence scale in the United States. Recently this instrument was revised with a number of changes. Those revisions resulted in the development of the Wechsler Adult Intelligence Scale-Third Edition in 1997. When a revision of a psychometric test occurs, it is important to have ongoing reserach to determine if those revisions result in any changes in the factor structure or reliability of the instrument. Most professionals agree that intelligence test scores are likely the chief indicator of ones potential and intellectual ability. Determining an intelligence score is a partial requirement to making an accurate diagnose of a Learning Disability (LD). Therefore, it is essential that any revisions in an intelligence test be examined to confirm the reliability and validity of the instrument. The purposes of this study are: (1) examine the factor structure of the WAIS-III for the LD sample, (2) to compare the profiles of learning disabled persons who have taken the WAIS-III to the standardization sample to determine if there is a discrepancy between the two profiles, (3) to determine if the sample, of 94 adults and adolescents diagnosed with a learning disability, displays an ACID profile that has depressed scores on the Arithmetic, Coding, Information, and Digit Span subtests, and (4) to determine of there is a Performance greater than Verbal discrepancy. Results of the confirmatory factor analysis, using data from the current sample, indicated that the four-factor solution provided by the Psychological Cooperation, (1997) is not a good fit for the data of the LD sample. Results from the ACID profile indicated that the sample population was significantly depresses on the Digit Symbol-Coding, Arithmetic, and Digit Span subtests. Results for the Performance greater than Verbal discrepancy was only significantly different for individuals diagnosed with a Reading disorder and a Writing disorder