Noting that growing evidence indicates that high-quality preschool child development programs contribute to the short and long-term development of children living in poverty, this digest summarizes recently reported experimental and quasi-experimental studies of Head Start and similar programs. Recently reported experimental studies include those of the Head Start Comprehensive Child Development Program, the Early Head Start program, the Even Start Family Literacy Program, and the Carolina Abecedarian Project. Quasi-experimental studies include the Head Start FACES project as well as studies of North Carolina's Smart Start program, Head Start, and the Chicago Child-Parent Centers. Findings of short-term studies question the value of case management as part of early childhood programs, provide guarded support for infant-toddler programs, and report that programs for 4-year-olds contribute to children's readiness to enter school and remain on grade. Long-term studies have found evidence of good preschool programs improving high school graduation rates and reducing the criminal activity of certain categories of participants. (Contains 16 references.) (KB)