<p>I've found the least effective discussions are those where all the students answer specific questions on the same topic.&#160; They are then to comment on at least three of their peer's initial post on the same topic.&#160; &#160;In technical writing, this often turns into micro-essays that say the same thing.&#160; It is really challenging for the students to make substantive comments to each other without getting into the "I agree" answers.&#160; They know they can't do this but are challenged to think up why they spend more time thinking up clever questions than discussing the topic.&#160; I think it works better to have them do some discussion of the topic but then move on into how they have or will put the topic into practice.&#160; This gives them more room for critical thinking and is more meaningful to them.</p>