A cognitive-social-developmental model of learning disabilities, chronic illnesses, and problems that affect children across diagnostic categories provides the rationale for the approach and the research presented here. Specifically, a dimensional approach is advocated which provides a way to take into account cognitive potential, academic performance, and behavioral and environmental information within and across diagnostic labels. The model underlying the approach is presented schematically in Fig. 19.1. For a complete discussion of it, see Hagen, Saarnio, and Laywell (1987).