Interpreting the WPPSI subtests scores of language impaired children—a structural approach

Abstract

The problem of characterising more specifically the cognitive requirements involved in subtests from standardised measures of intelligence represents a main problem in the research on exceptional populations. Seventy-five specifically language impaired (SLI) preschool children and 49 normally developing children were administered the Wechsler Preschool and Primary Scale of Intelligence (WPPSI). The scaled scores on the WPPSI were categorised according to Bannatyne's suggested regrouping to determine whether the pattern Spatial > Conceptual > Sequential could be observed in the data. The predicted pattern was only partially confirmed for language impaired children. The scaled scores on the WPPSI were then recategorized according to their structural complexity. Since structurally complex tasks contain more categories than the structurally simpler tasks, the pattern structurally Simple > Moderate > Complex was predicted and confirmed for language impaired children. Furthermore, it was hypothesized that the structurally Complex categories would discriminate better between language-impaired children and normally developing children than any other recoded categories. This hypothesis was confirmed. The low scores obtained by language impaired children on structurally Complex categories were interpreted as the result of capacity limitations in information processing rather than a deficit of any particular mental ability.

Confirmatory factor analysis of ITPA models with language–impaired children

“…What often is forgotten is that tests are powerful decision procedures and that they have a definite structure. This structure apparently influences performance in impaired populations (see Ottem, 1998Ottem, , 1999. A main characteristic of psychological tests is their structured form.…”

Confirmatory factor analysis of the WPPSI for language‐impaired children

“…The terms “knowledge dependent” and “processing dependent” are not easily applicable to standardized tests because this distinction is rarely made explicit on established assessment tools such as the WPPSI. In previous papers, a frame of reference for making explicit the processing load of subtests from standardized tests was presented by focusing on their structural complexity (see Ottem, 1998, 1999). In the present paper, the frame of reference will be used to draw a distinction between “knowledge dependent” and “processing dependent” subtests on the WPPSI.…”