The aim of this paper is to report on an ongoing experiment in an enquiry-based approach to feedback. Over the course of four years, almost 1800 students have studied a final-year undergraduate module involving a mid-term assignment and end of module examination. Feedback on the assignment is delivered through a process which involves the provision of feedback resources and action planning rather than any individualised comments on the piece of work. The results of the experiment to date suggests that this approach to feedback can have a positive effect on student performance as they make the transition from formative assignment to summative examination but that the main beneficiaries of that performance improvement are students who did well in the assignment rather that students who had average or poor performance.