This paper discusses the emergence of assessment for learning (AfL) across the globe with particular attention given to Western educational jurisdictions. Authors from Australia, Canada, Ireland, Israel, New Zealand, Norway, and the USA explain the genesis of AfL, its evolution and impact on school systems, and discuss current trends in policy directions for AfL within their respective countries. The authors also discuss the implications of these various shifts and the ongoing tensions that exist between AfL and summative forms of assessment within national policy initiatives.