Abstract: To study whether extrinsic motivational intervention would facilitate the effect of tutor learning, a Game Show feature was integrated into an on-line learning environment where students learn algebra equation solving by teaching a synthetic peer learner, called SimStudent. In the Game Show, a pair of SimStudents competed with each other by solving challenging prob-lems to attain higher ratings. To evaluate the effectiveness of the Game Show in the context of learning by teaching, we conducted a classroom study with 141 7th through 9th grade students. The results suggested that to facili-tate students’ learning, the Game Show setting must be carefully designed so that (1) the game show goal and learning goal are aligned, and (2) it fosters a symbiotic scenario in which both winners and losers of the game show learn.