The thesis investigates how master's students draw on past and co-occurring practices when doing a dissertation at the end of their taught programme. Dissertations invite students to utilize interests they bring to the master's degree. At the same time, dissertations are situated in discipline-specific fields and are an institutionally regulated type of assessment with particular requirements. Each dissertation thus becomes a site of interacting practices. The thesis is based on an ethnographically informed case study that involved twelve students from four different social science oriented master's programmes. It develops a theoretically and empirically grounded conceptualisation of practice, complementing and extending insights on the notion of literacy practices from New Literacy Studies and Academic Literacies, influenced by socio-philosophical practice theories, and based on the empirical case study. This framework, in which meaning is at the centre of what makes a practice, helps to explain how aspects of extra-disciplinary practices are appropriated into dissertation practices.