Evidence that teachers' short-term instructional effects persist over time and predict substantial long-run impacts on students' lives provides much of the impetus for a wide range of educational reforms focused on identifying and responding to differences in teachers' value-added to student learning. However, relatively little research has…

Teacher evaluation is at the center of current education policy reform. Most evaluation systems rely at least in part on principals' assessments of teachers, and their discretionary judgments carry substantial weight. However, we know relatively little about what they value when determining evaluations and high stakes personnel decisions. The…