Validation of a Learning Disability Index (LDI) Derived from a Principal Components Analysis of the WISC-R

Abstract

A learning disability index based on a principal components analysis of the WISC-R normative data has been developed to depict verbal or non-verbal deficits on that test. This index was calculated for the individual test performance of a total of 1550 children referred to a school board psychology service because of education difficulties. These children, subdivided by sex, and categorized as learning disabled or mentally retarded, returned mean scores on this index that were reliably different from the expected scores of the normative population; this difference revealed a verbal deficit in the test performance of the referred children. Reliable sex differences on this index appear in both the normal and abnormal groups.

Get full access to this article

View all access options for this article.

References

Inglis, J. & Lawson, J. S. (In preparation) A principal components analysis of the Kaufman Assessment Battery for Children (K-ABC): implications for the test results of children with learning disabilities.

Kaufman, A.S. & Kaufman, N.L. (1983) K-ABC. Kaufman Assessment Battery for Children. Interpretive Manual. Circle Pines, Minn.: American Guidance Service.

Lawson, J.S. & Inglis, J. (In press, a). Learning disabilities and intelligence test results: a model based on a principal components analysis of the WISC-R British Journal of Psychology.

Lawson, J.S. & Inglis, J. (In press, b). The psychometrie assessment of children with learning disabilities: an index derived from a principal components analysis of the WISC-R. Journal of Learning Disabilities.

Wechsler, D. 1949 Manual for the Wechsler Intelligence Scale for Children. New York: Psychological Corporation.

Wechsler, D. (1974) Manual for the Wechsler Intelligence Scale for Children-Revised. New York: Psychological Corporation.