This paper proposes a model of learning-oriented assessment to inform assessment theory and practice. The model focuses on three interrelated processes: the assessment tasks which students undertake; students' development of self-evaluative capacities; and student engagement with feedback. These three strands are explored through the analysis of assessment practice in context. The research method involves in-depth classroom observations of five recipients of awards for teaching excellence across multiple disciplines; and semi-structured interviews with these teachers and a sample of their students. Findings highlight assessment tasks promoting thinking and practicing in the discipline; the use of critical reviews to develop student understandings of quality work; and "same day feedback" to promote timely dialogues with students. The coherence of the model is discussed and some areas for further exploration are suggested.