This book provides new perspectives on assessment designed to support student learning in classroom settings. It examines the implementation of “Assessment for Learning” (AfL) at three levels: policy enactment by education systems, professional learning of teachers and school leaders, and practices in classrooms and schools. It reflects the issues, innovations, and critical reflections that are emerging in an expanding international network of researchers, professional development providers, and policy makers. Readers of this volume will encounter well documented accounts of AfL implementation across a large spectrum of conditions in different countries: Australia, Canada, England, Germany, New Zealand, Norway, Israel, Philippines, Scotland, Spain, Sweden, Switzerland, the United States. These contributions allow better understanding of the challenges that emerge in the transition from theory and policy to classroom practice. They also provide a wealth of ideas for implementing assessment for learning in an effective and sustainable manner.