Nurses' identities are constructed through their institutional belonging and the exercise of particular roles in the context of professional practices. Such roles and practices are themselves in part constituted through the performance of particular discourses. Research into such practices requires discourse analysts to become aware of and to understand the institutional and professional histories of those participants with whom they work, against which their professional practices are set. A collaborative exploration of how such professional participants, in this case, nurses categorise their communities of practice is one way in which this understanding can be attempted. Such a process poses challenges both to discourse analysts and to nurse professionals which may be met by close and collaborative inquiry.