There is now a large and growing evidence base that helping teachers develop their use of minute-to-minute and day-by-day assessment is one of, if not the most powerful ways to improve student learning. However, adopting formative assessment, or assessment for learning as it is sometimes called, involves far more than adding a few “quick fixes” to teachers’ classroom repertoires. It involves a fundamental shift in focus, from what the teacher is putting in to the process to what the students are getting out of it.