Assessment of Differences between Learning-Disabled and Normally-Achieving Students

Abstract

A discriminant function analysis of cognitive and achievement measures was undertaken to determine the effectiveness of differentiating between learning-disabled (LD) and normally-achieving (NA) students. Subjects were 37 LD and 44 NA subjects (mean age 8.8 years). Groups were matched for age, sex, IQ and socio-economic status. Results indicated no sex difference within LD and NA groups. The LD children performed significantly lower on all measures. The total test battery proved highly effective in differentiating between LD and NA children, yielding a hit rate of 90 per cent using Bayesian and Chi-square probability models. The Bender and VADS were most contributory while the self-concept measure (SPAS) proved the least in ability to differentiate between LD and NA groups. The VADS, in isolation, misclassified 40 per cent of the children (25 per cent of LD; 15 per cent of NA), supporting the position that test batteries have more utility and value than single measures.