Most academic conferences are preceded by some effort to make the sessions different from the usual format, but the usual format overwhelmingly prevails. That is: Each panel discussion runs no longer than two hours, during which two, three, or four specialists stand at a lectern and talk. Sometimes they will read a prepared paper; sometimes they will improvise; sometimes the final speaker will be charged with offering a critique of what has been said. At the end, questions from the audience will be invited. The enterprise will have a chair, who will introduce the speakers, call on people from the audience who wish to comment, and, when appropriate, end the session. The basic assignment of the chair is so simple that it is almost impossible to fail. Conference organizers usually give the CV's of the people to be introduced; the chair needs only announce some salient facts about each one and get out of the way. But chairing a session "can" be an art form. A good host can establish a friendly atmosphere in the room, make the speakers feel authentically welcome, and go a long way toward ensuring that interesting questions are asked and a solid discussion ensues. In this article, the author describes some of the steps a chair can take to encourage an effective session.