The Impending Demise of the Discrepancy Formula

This article calls into question the validity and utility of classifying poor readers into learning disability (LD) and non--learning disability (non-LD) categories on the basis of the discrepancy between their IQs and reading achievement scores (the Discrepancy Model). This form of classification of poor readers is based on two premises. First, the etiologies of these two forms of reading disabilities are different; therefore, there are qualitative differences in the cognitive makeups of these two groups of poor readers. Second, and consequently, the two categories of poor readers require different kinds of remedial treatment. The present review of research indicates that neither of these two premises is valid. In contrast, many research studies indicate that instructional methods which have disregarded the LD--non-LD distinction and focused their remedial efforts on the cause of the reading problem are generally successful in improving reading achievement. It is suggested that the practice of utilizing the discrepancy formula to classify poor readers into the LD and non-LD categories be abandoned and that a pragmatic approach which identifies the source of the reading problem for all children and focuses remedial efforts on that source be adopted (the Reading Component Model). The impact of the adoption of such a model on the learning disability field is discussed.