This article provides an analysis of assessment practices on one university-led teacher-training course in England, delivered across a network of further education colleges. After establishing that assessment practices are bound up in texts of different kinds, this article draws on two theoretical frameworks--institutional ethnography and actor-network theory--in order to explore how the work done by tutors and students on the course is mediated by texts. Through analysing the ways in which texts are used and the ways in which students and tutors respond to them, the paper suggests that assessment practices are in fact characterised by complexity and contingency which are masked by the dominant discourses of quality assurance and managerialism.