Longitudinal Studies of Alternative Types of Early Intervention: Rationale and Design

In 1985, the US. Department of Education awarded a competitively bid contract to Utah State University to conduct a series of longitudinal studies on the effects and costs of alternative types of early intervention programs for children having disabilities. Issues addressed by this set of studies included the effects and costs of varying (a) the intensity of intervention, (b) the age at which intervention is begun, and (c) the ways in which parents are involved in intervention programs. This article summarizes the historical context in which these studies were implemented, the rationale for conducting this type of study, and the procedures incorporated into the design of each study to ensure that the results would be useful to practitioners and other researchers.