There is a fine line when to let the students vent a little and when to stop them and return to the class at hand. I rely on the meeting moderator training I was given when I was working for IBM. There are many times when a meeting would stray a little from the topic at hand, we were taught to let it play out if it was constructive, but as soon as it became nonconstructive we would call to table it and either schedule a followup meeting or assign it to one of the participants as a work item. I have brought that to same training to use in the classroom by letting the students vent while they were being constructive (OK, not destructive) with in certain guidelines - I don't let them bad mouth a fellow student or an instructor. Terry