This report is based on a three-year study of the design of New York's Regional Network Strategy and its subsequent implementation activities, including the development of statewide professional development for members of the network involved in the state's strategy. The study is based on the idea that internal coherence--alignment and shared understanding of school improvement processes/approaches within and across levels of the multi-tiered educational system--will lead to a more effective school support system. An effective school support system is one that improves the capacity of districts and schools to effectively implement research-based strategies and supports in schools and classrooms. The report contains four sections following an executive summary, introduction, study overview and theory of action, and methodology and data collection. Section I, New York's Regional Network Strategy for School Improvement, contains: Overview; Key Features of the Regional Network Strategy; History and Background of the Regional Network Strategy; and Opportunities and Challenges. Section II, Implementation of the Regional Network Strategy, contains: NYSED (New York State Education Department) Regional Professional Development Initiative; and Participation, Next Steps and Impact. Section III, Cross Group Analysis, contains: Assessing Internal Coherence; Purpose(s), Rationales, and Assumptions; Strategies and Approaches to School Improvement; Roles and Responsibilities, including How Groups Interact with Each Other; and Leadership Interactions. Section IV contains policy recommendations. Appendices A-E provide: Study Questions and Protocols; Data Collection Activities, Dates, and Participants; Regional Network Partner Summary Reports; Listing of NYSED Policy Documents; and NYSED Regional Professional Development Initiative and Supplemental Materials. (Contains 3 figures and 6 tables.) [This publication was produced by The Education Alliance at Brown University.]