  We describe a study in which introductory physics students engage in
reflection with peers about problem solving. The recitations for an
introductory physics course with 200 students were broken into the "Peer
Reflection" (PR) group and the traditional group. Each week in recitation,
students in the PR group reflected in small teams on selected problems from the
homework. The graduate and undergraduate teaching assistants (TAs) in the PR
group recitations provided guidance and coaching to help students learn
effective problem solving heuristics. In the recitations for the traditional
group, students had the opportunity to ask the graduate TA questions about the
homework before they took a weekly quiz. On the final exam with only
multiple-choice questions, the PR group drew diagrams on more problems than the
traditional group, even when there was no external reward for doing so. Since
there was no partial credit for drawing the diagrams on the scratch books,
students did not draw diagrams simply to get credit for the effort shown and
must value the use of diagrams for solving problems if they drew them. We also
find that, regardless of whether the students belonged to the traditional or PR
groups, those who drew more diagrams for the multiple-choice questions
outperformed those who did not draw them.
