ABSTRACT
The special education research literature is composed primarily of cross-sectional studies in which selected individuals or groups of individuals are studied at a particular time point in their lives. These studies have yielded rich descriptions of a range of exceptional conditions and problems at various ages, including learning disabilities (LD) and social and adjustment problems. However, cross-sectional studies do not allow firm inferences about the links between time periods, nor do they identify the processes which explain continuities and discontinuities in development. Understanding exceptional conditions requires study of the same individuals over time, as one of the goals of research from a developmental perspective is to specify the causal mechanisms underlying specific disorders, not just to describe particular conditions at a single time point. As well documented in the literature on children with disabilities and those considered “at risk,” the developmental paths and the long-term outcomes for individual children within groups differ greatly. Some overcome the odds against them and become well adjusted, competent adults, whereas others have continuing personal, social, and educational problems (Werner & Smith, 1992). Thus, the need for longitudinal studies.
