Factor structure of the Wechsler Intelligence Scale for Children-Revised,Peabody Picture Vocabulary Test,and Peabody Individual Achievement Test in a psychiatric sample

This study analyzed the factor structure of the Wechsler Intelligence Scale for Children-Revised (WISC-R), the Peabody Picture Vocabulary Test (PPVT), and the Peabody Individual Achievement Test (PIAT) in a psychiatric sample that ranged in age from 6 to 16 years (mean age = 11.1 years; SD = 3.0). The resultant factor structure of this sample was compared with patterns reported on normal and learning-disabled children. The subjects were 329 children under inpatient and outpatient care who had been referred for emotional disturbances. The results were similar to previous factor analytic studies of the WISC-R and PIAT, showing four factors: Verbal Comprehension, Verbal Achievement, Perceptual Organization, and Number Facility. The implications for the interpretation of these tests in a psychiatric sample and the appropriateness of a maximum likelihood technique in analysis of psychometric data are discussed.