This article considers a hypothetical decision by a hypothetical learner about whether or not to participate in an online "discussion", viewed through the lens of risk analysis. It begins with the premise that participation online is desirable but that it involves the participant in risk, a fact that needs to be acknowledged and taken into account in the design of online learning. The article refers to previous work done on understanding online interaction through discourse analysis, which found instances of confusion about the interactive rules (or genre) that were appropriate to the online interaction. The article argues that such an uncertainty may constitute an important risk factor which may affect online participation. The element of risk is then more fully examined through a table of risk analysis; notional risk values are ascribed to a number of risk factors facing the potential online participant, calculated according to the seriousness and probability of the risk. These are weighed against likely benefits and summed to give an overall risk score. This approach is proposed as a method of integrating research findings from a range of sources, providing pointers for future research and of identifying ways to reduce the risks of online participation. (Contains 1 table.)