John Hattie and Helen Timperley states that feedback is one of the most powerful influences on learning and achievement, but this impact can be either positive or negative. Its power is frequently mentioned in articles about learning and teaching, but surprisingly few recent studies have systematically investigated its meaning. This article provides a conceptual analysis of feedback and reviews the evidence related to its impact on learning and achievement. This evidence shows that although feedback is among the major influences, the type of feedback and the way it is given can be differentially effective. A model of feedback is then proposed that identifies the particular properties and circumstances that make it effective,
and some typically thorny issues are discussed, including the timing of feedback and the effects of positive and negative feedback. Finally, this analysis is used to suggest ways in which feedback can be used to enhance its effectiveness in classrooms. They also supports although it is often mentioned in articles about learning and teaching, surprisingly few recent studies have systematically investigated the meaning of feedback in classrooms. In this article, we begin with a conceptual analysis of the meaning of feedback and a synthesis of the evidence related to the power of feedback to improve teaching and learning. We then propose a model of feedback that is used to identify the circumstances under which feedback has the greatest impact. Specifically, the research evidence related to the different types of feedback and their effectiveness in terms of promoting student learning are discussed, the different ways students deal with feedback are described, and the relationship between assessment and feedback is provided. Finally, the model, together with the evidence underpinning it, is used to show how feedback can be used to enhance classroom learning and teaching.