This paper uses the case-study method to examine detailed data related to student and tutor usage of an asynchronous discussion board as an interactive communication forum during a first-semester associate degree course in applied psychology at the City University of Hong Kong. The paper identifies "what works" in relation to discussion board use, demonstrating how students might gradually create an online community of their own, but only if prompted in a timely and appropriate way by the course structure. It also identifies three distinct phases in online interaction and suggests these might, to some extent, be mediated by assessment tasks. (Contains 2 tables and 2 figures.)