This literature review summarizes the research on early childhood education, parent education, and family support programs, and reports on relevant research in progress. Key findings are discussed in the context of the results of studies over 3 decades. The literature indicates that conceptual underpinnings and theoretical constructs underlying various intervention strategies have evolved over 30 years. The first wave of programs focused on improving the child's cognitive functioning or on training the parents or caregivers as the intervenor by attempting to alter parenting behaviors to promote cognitive functioning, although neither type of program was entirely exclusive. Most programs still consciously address both the child and the parent. The range of expected outcomes has broadened over the years, from a narrowly cognitive focus to a concentration on the entire range of developmental outcomes for the child and to the improvement of life outcomes for the parents. The review of the research also indicates that interventions beginning earlier in the life cycle (i.e., beginning prenatally rather than when the child is near to school entry) are more effective than later interventions, and that comprehensive interventions are complex and have not been studied extensively. The lack of an adequate body of research on collaborative, multifocused, intensive, comprehensive programs is the most serious limitation to date--from the perspective of policymakers seeking evidence in favor of one program strategy over another--and should be pursued. (Contains 185 references.) (DR)