The irrelevance of IQ to the definition of learning disabilities: Some empirical evidence

The relevance oflQ to the definition of learning disabilities is a much-debated issue. In this article, the effect of not using IQ in the identification of children with reading disabilities is demonstrated. Two classification procedures, differing in their use of IQ, are compared. The first conclusion is that abandoning IQ in classification has a very limited impact on the number of children identified as reading disordered. Our data demonstrate that, if IQ is used, more high IQ children are classified. Another finding pertains to the effect of a restriction oflQ range. The number of children classified as reading disordered is a function of the IQ range. The idea of discrepancy is an impor-tant feature of the definition of learning disabilities (Siegel, 1989a, 1989b). An analysis of the literature reveals that several procedures are available to measure discrepancy (e.g.