The purpose of this synthesis of the literature on charter school effectiveness is to develop a research agenda on the topic and to propose action that will lead to improved performance of charter schools. To accomplish these goals, background information is first provided including: a definition of charter schools; statistics on charter schools; charter school legislation in six sample jurisdictions; arrangements for the creation, governance and management of charter schools; and the new roles and relationships that have developed over the past fifteen years as the charter school concept has matured. Then, the meaning of charter school effectiveness and factors that are associated with varying degrees of charter school effectiveness are explored. Finally, tentative conclusions are reached as to the focus of future research incorporating selected interventions designed to improve charter school performance.