Here are some sample roles your students should be using:
Leader/ Facilitator - This person makes sure that everyone gets
a chance to speak and/or a job to do.
Materials Manager - This person is responsible for gathering
materials needed for the activity, and returnin them properly.
Recorder - This person writes down what happens during the activity.
Reporter - This person communicates the group's results to the
whole class.
Encourager - This person makes it there job to encourage others,
by finding something positive to say about things suggested.