This paper reviews research findings concerning the effects on young children of major Federal programs in education and child care. It offers a summary rather than a detailed view of research on the impact of programs, and is based primarily on major program evaluation reports and research reviews. In addition, it draws upon a small number of individual articles and studies which provide supplementary evidence regarding the effects of intervention on children. The major programs examined are Head Start, Parent-Child Centers, Home Start, Follow Through, the Handicapped Children's Early Childhood Education Program, "Sesame Street," and "The Electric Comapny." The paper also examines the impact of day care experiences on young children, drawing on several recent reviews of research on day care (in general, not as part of a Federal program), prepared for the Office of the Assistant Secretary for Planning and Evaluation. Each section discusses a topic in relation to specific programs. Sections cover: short term and long term effects on children's cognitive and affective development; short and long term effects on non-cognitive outcome measures (socioemotional development, family change, community change); the effectiveness of curricula and treatment structure; assessment of program implementation; effects of parent involvement; effects of programs on children with different characteristics; and timing of intervention. (Author/SB)