A conceptual overview of the regression discrepancy model for evaluating severe discrepancy between IQ and achievement scores.

A conceptual overview of the Regression Discrepancy Model (RDM) for determining severe discrepancy between IQ and achievement scores is presented in order to enhance understanding of the model without the use of the complex mathematical equations that constitute the model. The six specific goals of the RDM are identified, and figures illustrate the manner in which the model accomplishes each goal. Figures are also provided from a RDM computer output showing the basic outcomes of the model. Advantages and disadvantages of the RDM are discussed to further promote understanding of the model.