In Practice

Announce rules of conduct for courteous exchanges at the start of a course
Post participation expectations and associate points with substantive contributions
Start students off with an ungraded discussion, perhaps an ice-breaker, in order to work out any potential problems in the beginning
Set up specific forums for specific purposes. For example, have a place for students to post general questions rather than emailing you directly. You can also provide places where students can help each other or ask technical questions, as well as a place for casual conversation
Create a forum for "Weekly Discussions" and then a separate topic within each week in order to avoid being overwhelmed by the number of messages about a particular topic
Assign meaningful tasks. Carefully select topics that promote active discussion
Keep discussion focused -- reframe questions if the discussion goes off topic
Provide students with time to reflect, formulate ideas, and give thoughtful responses
Assign private discussion space to small groups of 3 to 7 students. Share group achievements with the whole class
Invite a guest expert to join the discussion for a short time
Extend learning by recommending additional resources

The University of Newcastle, Australia