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

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.