Generating true learning dialogue as opposed to a collection of loosely affiliated posted messages on a class discussion board can be challenging. This paper presents the results of a cross-case analysis of nine naturalistic case studies of online classes, looking at how activity design and facilitation factors affected various dimensions of student participation. Findings show that use of guidelines, deadlines and feedback and type of instructor presence affect the resulting discourse in an online class. Additionally, the paper explores how particular types of learning activities are better suited to generating discussion than others and how the integration of discussion activities with the rest of the course activities and requirements impacts learner motivation and participation.