Ask a question or make a comment that shows you are interested in what another person has said.
Ask a question or make a comment that encourages someone else to elaborate on something he or she has said.
Make a comment that underscores the link between two people’s contributions. Make this link explicit in your comment.
Use body language to show interest in what different speakers are saying.
Make a comment indicating that you found another person’s ideas interesting or useful. Be specific as to why this was the case.
Pose a problem or a dilemma.
Play the devil’s advocate: listen carefully for any emerging consensus, and then express a contrary viewpoint, whether you believe it personally or not.
Contribute something that builds on or springs from what someone else has said. Be explicit about the way you are building on the other person’s thoughts.
Make a comment that at least partly paraphrases a point someone has already made.
Make a summary observation that takes into account several people’s contributions and that touches on a recurring theme in the discussion.
Disagree with someone in a respectful and constructive way.
Point to a specific passage in the assigned text that is particularly helpful either to illuminate or to problematize the current direction of the discussion.
C.f. Stephen D. Brookfield and Stephen Preskill, Discussion as a Way of Teaching: Tools and Techniques for Democratic Classrooms, 2nd edition (San Francisco, CA: Jossey-Bass, 2005