The studies discussed in this paper are federally funded intervention studies involving preschool children and follow-up studies of early elementary school children. This paper is divided into three major sections: Day Care Intervention Studies, Child Development Intervention Studies, and Child Advocacy Programs. The purpose of this review is to: (1) describe the ongoing studies funded in fiscal year 1970-71 of intervention with preschool and early elementary school children; (2) discuss pertinent findings when they are available, and (3) identify existing gaps and needs in the longitudinal study of preschool intervention. A summary chart highlighting the overall needs and gaps in federally funded early childhood intervention studies precedes each paper. (Author/CS)