Little is known about how classroom practice changes. Over the last two decades deliberate and determined steps have been made to improve schooling in the United Kingdom (UK), and yet the place of classroom practice, or the mechanisms by which it changes, remain largely unremarked and un-researched. How is it that serious efforts to improve classroom practice work, and how do these changes result in differences in pupil learning? This book charts current developments in the practical business of changing classroom practice to make schools more effective.