Although becoming widespread, especially in view of No Child Left Behind (NCLB) and without a universally-accepted definition, most discussions of standards-based reforms (SBR) include certain commonalities, including: (1) Academic expectations for students; (2) Alignment of key elements of the educational system to promote attainment of these expectations: (3) Assessments of student achievement to monitor performance; (4) Decentralization of responsibility for decisions relating to curriculum and instruction to schools,: (5) Support and technical assistance to foster improvement of educational services: and (6) Accountability provisions that reward or sanction schools or students based on measured performance. The SBR movement reflects a confluence of policy trends, particularly, a growing emphasis on using tests to monitor progress and hold schools accountable and the belief that school reforms are most likely to be effective when all components of the education system are designed to work in alignment toward a common set of goals. Additional key ideas include an emphasis on using information produced by the system to guide instructional decision-making; an emphasis on using standards to promote instruction that is academically challenging rather than focused on low-level skills; the importance of similarly high expectations for students with different socioeconomic, racial/ethnic and linguistic backgrounds; and, perhaps most significantly, an education system in which policy and practice are driven in large part by the measurement of academic outcomes derived from large-scale assessments. Some of the hopes of early reformers have been at least partially realized, but at the same time, some of the fears of early critics have materialized. This paper summarizes what is known about SBR and suggests a foundation for a revised federal role in promoting high-quality standards and assessments. Ongoing efforts to improve the knowledge base and disseminate what is known to decision makers at all levels will be fundamental to the development of SBR systems that promote high-quality teaching and learning. (Contains 5 footnotes.)