This panel explores two questions: what are we learning about the measurement of effective teaching and how are measures of effective teaching being used to inform public policy? The session begins with two papers on the measurement of effective teaching. “The State of the Art in the Research on Value-Added Models of Teacher Performance: Taking Stock of What We Know and Don’t Know” summarizes findings from a major project undertaken by the authors to understand the methodological problems and solutions analysts must confront when attempting to estimate teacher value added models. The authors conclude with practical advice for researchers and policymakers for computing and using value-added performance measures. “Forming Composite Measures of Effective Teaching” addresses how to combine teacher value added measures with other measures from classroom observations and student surveys using new data from the Measures of Effective Teaching (MET) project. Understanding this topic is particularly important as states and districts move forward with evaluating, paying, and potentially firing teachers based on both value added and classroom observation scores. The session will then turn to two examples of how teacher effectiveness measures are used in real-world policy applications. “The Size and Reliability of Teacher Training Effects in Texas” explores the question of whether we can use teacher value added estimates to evaluate the effectiveness of educator preparation programs. As envisioned by the Obama administration and some state policymakers, program evaluations should be based on the effectiveness of the teachers graduated by each program, with teacher effectiveness measured in terms of student outcomes such as test scores and graduation rates. Based on an analysis of first, second, and third year teachers, the authors report that many programs graduate small cohorts and that many of the graduates of these programs teach in small schools. The authors conclude that most program effects are small and imprecisely estimated. “The Distribution of Effective Teachers in North Carolina” examines a question critical to evaluation of many state Race to the Top teacher initiatives: whether teacher effectiveness as defined by teacher value added is equitably distributed across different student subgroups, classrooms, schools, and districts. In contradiction to prior research using proxies of teacher quality such as years of experience and credentials, the authors find virtually no difference in the teacher effectiveness scores between black and white students and poor and non-poor students. Classrooms with students who were higher achievers in the previous year, however, tend to be assigned more effective teachers, a tendency that is especially strong in high-poverty schools. Low poverty schools, on the other hand, tend to assign more effective teachers to the lowest achieving students, at least in math.