In the wake of national interest in teacher evaluation, this book examines what we have learned about how and whether teacher evaluation holds teachers accountable and improves their practice. Drawing on literature in psychology, economics, and sociology, this multi-disciplinary and multi-perspectival book explores teacher evaluation's intended goals of development and accountability, as well as its unintended consequences, especially as they relate to equity. Blending theory from diverse disciplines with decades of research, this book provides new insights into how teacher evaluation has played out in schools across the United States and offers recommendations for research, policy, and practice in the years to come. Insights include how to embed teacher evaluation in a larger culture of continuous learning; rethinking assumptions on accountability and development aims; and highlighting the importance of equity in the design, implementation, and outcomes of teacher evaluation. Every chapter concludes with practical recommendations informed by theory and research to guide policymakers, researchers, and district and school leaders as they seek to understand, design, and implement better teacher evaluation systems.