This volume, part of the interim report on the National Home Start Evaluation, includes cost of the 16 Home Start projects and outcome data from the six summative sites. Findings and recommendations are presented on the intra-project cost-effectiveness of Home Start and the cost-effectiveness of Home Start as a Head Start option. Home Start, a federally-funded 3-year (1972-1975) home-based demonstration program for low-income families with 3- to 5-year-old children was designed to enhance a mother's skills in dealing with her own children and to provide comprehensive social-emotional, health and nutritional services. Cost findings are presented in detail in Chapter II. Both OCD dollars spent on Home Start as well as "in-kind" levered resources from other government agencies and private sources are presented so that a full comparison between projects can be made in terms of total monetized resources delivered to project families. Chapter III sets forth an analysis of intra-project efficiency in terms of technical efficiency (the home visit content and length) and cost efficiency. The chapter ends with a presentation of hypothetical model budgets for different project sizes located in different parts of the country designed to assist OCD in making future decisions about funding home based options. Chapter IV contrasts Home Start costs with Head Start costs at four sites. (Author/MS)