A structure for online discussion within a framework for deep learning provides three strategies for dynamic online discussion; flexible peer, structured topic, and collaborative task discussion. This article examines the discussion structure and the three separate roles demonstrated by the instructor in the promotion of deep learning through the use of online discussion. The roles of the instructor are critical in the implementation of discussion strategies and design of student tasks for significant learning in online collaborative environments. This article has theoretical and practical implications for instructors in designing and facilitating asynchronous and synchronous discussion. (Contains 3 figures.)