Much of the methodological literature currently influential in the education policy community has focused on research studies and assessments intended to support generalizable conclusions about "what works" or what students "know and can do." Until recently, far less attention has been paid to how educators actually interpret and use this information in making routine decisions in their local contexts of work; to what kinds of evidence may be needed to support those decisions; to the social structures, organizational routines, and patterns of interaction that shape the ways in which information is interpreted and used; or to how these practices might be improved to better support learning. The standards-based reform movement, with its emphasis on performance-based accountability, has further focused attention on a particular source of evidence--standardized tests of student achievement--and a "theory of action" for how this information would function within the system. This volume and the small but growing literature base on which it draws decenter, complement, and challenge studies of the impact of standards-based accountability to consider questions about how education professionals (might) actually interpret and use tests and other sources of evidence to make routine decisions in their daily work; about how these practices shape and are shaped by organizational structures, routines, and cultures; and about the sorts of learning and professional agency that are fostered. The volume also highlights technical infrastructures that have emerged concomitant with the standards-based reform movement to enable the collection, distribution, consolidation, and reuse of evidence as has not been possible before, along with the social practices through which they are implemented. As the chapters illustrate, professionals working in different contexts have different decisions to make, different sources of evidence, different resources for interpreting the available evidence, and different constraints on their practice. Chapter authors analyze different practices of constructing and using evidence in classrooms, teacher communities, schools, and school districts, with particular attention to promising examples; consider the roles that district, state, and federal education agencies can play in supporting sound practice; and provide historical background on how educators have used evidence to improve practice, theoretical resources for studying the interpretation and use of evidence in educational organizations, and epistemological resources for warranting the different kinds of decisions that are made. (Contains 9 tables, 22 figures, 6 illustrations and 66 notes.)