You can lead an effective discussion, even when the class size is very large. The Fishbowl Technique needs two things in order to work well:

1. sufficient classroom space for a small group of student to sit in a circle where everyone can see them
2. acoustics – natural or enhanced – that allow the discussion to be heard by all

While there are several variations on the technique, the basic setup goes like this:

Set a small number of chairs in a circle.  These form the “fishbowl.” The first group of students each take a seat, leaving one chair empty. This small group begins the discussion, while the rest of the class follows by listening.

When a new person wants to join the discussion, they take a seat in the empty chair. At this point, someone else must voluntarily leave the fishbowl so that one chair is always empty. People move in and out of the fishbowl as the discussion continues, providing the entire class an opportunity to participate.

The discussion topic can be introduced ahead of time to allow students to prepare, or it can be used to explore material recently introduced. Variations on the fishbowl include filling all the chairs for a set time, then replacing all the seated participants at set intervals.

Flickr photo Creative Commons licensed by bloomgal.