After a decade of studies, this report draws together RAND's research on New American Schools, highlighting the organization's significant contribution to comprehensive school reform and noting the challenges that came with implementing whole-school designs. About a decade ago, New American Schools (NAS) set out to address the perceived lagging performance of American students and the lackluster results of school reform efforts. As a private nonprofit organization, NAS's mission was-and is-to help schools and districts raise student achievement levels by using whole-school designs and design team assistance during implementation. Since its inception, NAS has engaged in a development phase (1992-1993), a demonstration phase (1993-1995), and a scale-up phase (1995-present). Over the last ten years, RAND has been monitoring the progress of the NAS initiative. This book is a retrospective on NAS and draws together the findings from RAND research. The book underscores the significant contributions made by NAS to comprehensive school reform but also highlights the challenges of trying to reform schools through whole-school designs. Divided into sections on each research phase, the book concludes with an afterword by NAS updating its own strategy for the future. This book will interest those who want to better understand comprehensive school reform and its effects on teaching and learning within high-stakes accountability environments.