This paper summarizes some of the main conclusions of the Study of Dissemination Efforts Supporting School Improvement, specifically those regarding the process of innovation implementation. The focus is on the contributions of potential assisters to various implementation outcomes, from which implications for policy and practice are derived. The major emphasis is on the crucial (and unanticipated) role of district-level personnel in catalyzing and coordinating successful efforts. The primary conclusion derived from the research is that, in any school improvement effort, the key actors tend to contribute in different ways: principals contribute to both practice-related mastery and plans for continuation; local facilitators contribute to both teacher commitment and perceived efficacy; and external facilitators contribute to practice-specific mastery. Practical implications of these findings are provided for principals, central administrators, and facilitators. The paper concludes with three general recommendations related to coordinating assistance in school improvement efforts: (1) both local and external facilitators should perceive implementation in terms of the 10 outcomes listed in table 1; (2) local and external facilitators should work out a division of labor; and (3) facilitators should locate and involve a central administrator committed to successful implementation. (TE)