This study evaluated the effect a developmentally appropriate curriculum, implemented as part of a Head Start Transition Project for public kindergarten through third grade to maintain and enhance the benefits attained by Head Start children and their families. Participating were two cohorts of students in demonstration and comparison classrooms from eight schools in Worchester, Massachusetts. Classroom observation data were collected at the end of each of the 5 years using the Assessment Profile for Early Childhood Programs: Research Version; the ADAPT: A Developmentally Appropriate Practice Template was added in Year 3. Children were followed from kindergarten through grade 3, with Cohort 1 beginning kindergarten in 1992 and Cohort 2 in 1993. At demonstration schools, monthly teacher in-service training was given during the first 2 years and additional funds were made available to purchase materials. Comparison schools did not receive any Transition Project resources, although some underwent considerable reform and received considerable classroom resources. Findings indicated that classrooms receiving resources to create developmentally appropriate classrooms and with a principal committed to the philosophy of developmentally appropriate practice were further advanced in providing a developmentally appropriate environment than classrooms which did not receive or fully implement these resources. Further, there was a general decrease in the use of developmentally appropriate practices over the years, but an increase within classes from year to year. (Appendices include descriptive data summaries. Contains 13 references.) (KB)