A Meta-Analysis of the Validity of Wechsler Scale Profiles and Recategorizations: Patterns Or Parodies?

Abstract

The techniques of meta-analysis were used to arrive at a quantitative synthesis of the results of 94 studies of the validity of Wechsler regroupings for differential diagnosis of learning disabilities. The primary finding indicated that no recategorization, profile, factor cluster, or pattern showed a significant difference between learning disabled and normal samples. The learning disabled group revealed about average performance and demonstrated less variability than the normal comparison group. Although differences emerged within the learning disabled group, no regrouping scheme was found exhibiting a uniqueness for learning disabilities that might be useful in differential diagnosis. Based on these results it was concluded that profile and scatter analysis is not defensible and that use of the Wechsler Scales should focus only on global intelligence assessment.