There is a growing awareness of the need to move beyond generic approaches to teaching, learning and assessment (TLA) to consider the importance of context in shaping TLA practices. However, efforts to engage with context have focused primarily on disciplinary epistemologies and in particular the differences between hard, soft, pure and applied disciplines. This paper argues that disciplines should be considered not just in terms of epistemological differences, but as socially situated practices. This research is based on interviews with 30 academics across 4 merging disciplinary workgroups of a South African university. A framework for exploring TLA workgroup cultures is proposed, drawing on a modified communities of practice theory (COPT), that moves beyond functionalist accounts of socially situated practices in COPT to focus on how departmental TLA cultures mediate between individual agency and a range of structural factors. When looking at disciplinary TLA cultures through this lens this research found that what was more significant than the differences between disciplines based on epistemological difference were differences in the ways academic workgroups mediated between the knowledge structures of the discipline and the challenges of a society in transition with competing expectations of students, knowledge, the state, marketization, and the demands for reconstruction and development. It was thus the work done in localised workgroups on disciplinary epistemologies in response to a range of contextual factors that was found to be more significant than differences between the disciplines in defining TLA cultures.