In higher education (HE), effective feedback on student assessments plays a vital role in retention and in the development of self-regulating learners, particularly in the first year. In distance learning, where large population modules are common, assignment feedback is generally supported by standard marking guides, issued to the numerous tutors responsible for assessing student work. In this paper, we develop a taxonomy of feedback and report on the results of a survey of tutor attitudes to, and strategies for, providing feedback on a very large Level 1 Open University module. We analyse the extent to which the marking guides afford adequate support for truly effective feedback, and make a number of recommendations for reworking assessment regimes and marking guides. (Contains 3 figures.)