What to do about top students making other students lose confidence? About once a year, I end up with a section with a student who is well ahead of others in the course. Often, these are students auditing the course, but sometimes are senior students attending 100-level courses or students majoring in the subject attending a course for non-majors in a made-simpler-for-non-majors course.

Such students are often eager to learn, quick to volunteer to come to the board or volunteer their work for peers to check (e.g. in a writing course), active in discussions, and they tend to take charge of group work. This does not seem like behavior I should discourage. Yet, in such sections, I notice significantly reduced confidence, participation, and engagement among other students, who seem uncomfortable with having a strong student constantly outdo them. Other sections tend to have active lessons, with many students eager to volunteer or join in a discussion, but in these sections, the class atmosphere is quiet and I'm reduced to calling on names and getting unwilling participants to carry the course along.

What can I do to turn this situation around?
When I was a TA, I always found these types of students the most difficult to handle.  You don't want to crush their enthusiasm, but you also don't want to let them dominate and make it harder for other students to learn. It's also important to remember that just being way out ahead of other students doesn't cause this phenomenon: you're dealing with somebody who is both ahead and feels a need either to show off or to receive affirmation from you the instructor.

Some tactics that I found effective were:


Establishing clear ground rules that people had to raise their hands to be acknowledged, rather than just shouting out.  Then you need to become comfortable waiting long enough for other students to raise their hands too.
Saying things like "Everybody needs a chance to learn, so I'm going to make sure that we get some folks up to the board who haven't been there very often."
Rather than asking for volunteers, actively calling on students who have been silent.  It's embarrassing for them, but if you do it kindly and make it into a guided learning experience at the board rather than a test of their abilities, it can be a very good thing.
Privately discussing with the enthusiastic student, something like: "I'm very pleased at how well you're mastering the material, and I need to make sure other students have a chance to have the same learning opportunities, so I'm going to call on you less often."
Giving "extra credit" work that the enthusiastic student can be working on to occupy themselves.


In all cases, what you want to emphasize is the importance of active learning by participation, and how it's important for all students to have those opportunities.

Addendum: I was talking about this with my wife and she told me about a tactic that she uses that I think is another excellent addition to the toolkit:


Divide the class up into rough geographic zones and call on zones round robin, e.g. "Left side answered the last question.  Let's get an answer from the middle now."