This paper reviews research on learner and tutor interaction in asynchronous computer-mediated (ACM) conferences used in distance learning. The authors note claims made for the potential of ACM conferences to promote higher-order critical inquiry and the social construction of knowledge, and argue that there is a general lack of evidence regarding the actual achievement of these aims in such conferences. We present and discuss the relevant research literature currently available on the effects of social presence, the tutor's teaching and moderating strategies, and task type. The paper concludes with recommendations for future research in each of these areas. (Contains 4 tables.)