AbstractAssessment and feedback is an area where mathematical sciences departments have invested significant effort in recent times. Particular challenges have been identified relating to timely and detailed feedback, both of which are important given the widespread use of formative, and typically weekly, problem sheet assessments to aid and structure the mathematical development of learners. Here, we report on a first cycle of action research, linked to the implementation of a revised curriculum in a large UK research-intensive mathematical sciences department, which was designed to enhance the feedback received by students and their subsequent engagement with it. Whilst we draw upon the results of a survey of 74 undergraduate students, we also describe the pilot of a method for providing video-based marking and feedback. Our results show the importance that students within the mathematical sciences place upon feedback as part of their learning experience, but also that amongst those undergraduates surveyed, there was no clear consensus as to whether they had received sufficient feedback upon their work. The findings reinforce the need for students themselves to engage with their mathematical feedback in a meaningful way, and significantly they indicate that the feedback perceived as most valuable involves opportunities to engage in dialogue about their work with either their peers, postgraduate teaching assistants or academic members of staff. As such, the emphasis that departments place upon providing ‘detailed written comments’ on formative work appears not to be valid, and instead more ‘dialogical’ or ‘interactive’ mechanisms for providing feedback in mathematics may have the potential to yield more effective results.