The current high-stakes accountability environment brought on by the federal No Child Left Behind Act (NCLB) places great pressure on school districts to demonstrate success by meeting yearly progress goals for student achievement and eventually demonstrating that all students achieve at high standards. In particular, many urban school districts--with their high-poverty and low-achieving student population and constraints due to insufficient human, physical, and financial resources and high rates of turnover in school and district staff--face great challenges in meeting these goals. In fall 2002, the RAND Corporation initiated a study to analyze three urban districts' efforts to face these challenges and improve the instructional quality and performance of their schools. The study also sought to assess the contribution to these efforts made by an intermediary organization, the Institute for Learning (IFL). District reform efforts in four areas were closely examined: (1) promoting the instructional leadership of principals; (2) supporting the professional learning of teachers, in particular through school-based coaching models; (3) specifying curriculum; (4) and promoting data-based decision making for planning and instructional improvement. Also examined was the impact of the IFL on these instructional improvement efforts. This monograph presents findings from that three-year study. It describes the districts' work in each area of reform, identifies common constraints and enablers of district success, assesses the nature and impact of district-intermediary partnerships, and makes recommendations for districts undertaking similar instructional reforms.