The Admin. on Children, Youth & Families (ACYF) designed Early Head Start as a two-generation program to enhance children¿s development & health, strengthen family & community partnerships, & support the staff delivering new services to low-income families with pregnant women, infants, or toddlers. Today (2002), the program operates in 664 communities & serves some 55,000 children. At the same time, ACYF selected 17 programs from across the country to participate in a rigorous, large-scale, random-assignment evaluation. This report summarizes the research programs, which includes all the major program approaches & are located in all regions of the country & in urban & rural settings. The families they serve are highly diverse. Illus.