|As every teacher knows, what students learn as a result of any particular sequence of instruction is hard to predict”what students learn is not necessarily what we teach. This is why assessment is perhaps the central feature of effective practice”assessment is the bridge between teaching and learning. It is only by assessing that we can find out whether the instructional activities in which students have engaged have resulted in the intended learning. Without assessment, we might as well be speaking our lessons into a video camera that is relayed to students in another room. Of course the idea that assessment can support student learning as well as measure its extent is nothing new”the term œFormative assessment has been around for 50 years”but over the last few years, evidence has been accumulating that attention to assessment as part of instruction is one of the most powerful ways of increasing student engagement and achievement. As a result, formative assessment, or œassessment for learning as it is sometimes called, has become a policy priority for many schools. Unfortunately, however, in many cases, attention has focused on tracking pupil progress which has limited impact on student achievement.