This paper reports findings from the National Institute of Education's Napa County Project, one of four follow through projects funded over a period of four years to develop and implement instructional programs that would improve teaching practices, increase students' academic engaged rates, and increase gain on reading and mathematics achievement tests. The assumptions of the follow through project were that effective staff development would lead to improved instructional practice and the improved instructional practice would help students be more productively engaged in academic tasks. In the Napa County Project, which involved two schools with the largest percentage of children eligible for Chapter I in their districts, Madeline Hunter's Instructional Theory into Practice (ITIP) was selected as the training model. After a planning phase, begun in 1981, the project implemented the training program, collected implementation and student data, and revised the training program on the basis of yearly evaluations. Instruments to measure program implementation and rate of students engaged were developed and piloted in kindergarten through fourth grade classrooms. Two additional schools were selected to provide a basis for comparisons. Results of numerous analyses indicated that the primary impact of the program culminated at the end of the second year of implementation. Reasons for the subsequent decline are briefly discussed. (RH)