We have developed Teachable Agent environments that use learning by teaching with metacognitive support to help middle school students learn about complex science topics. To demonstrate the effectiveness of this approach, we have run studies that compare three systems where (i) students are taught by an agent, (ii) students teach a computer agent, and (iii) students teach a computer agent and receive metacognitive support while teaching. Students ’ activities on the system, captured in log files, were coded using six primary learning activities. In this paper, we analyze behavior fragments systematically derived from the activity sequences, and identify behaviors that correlate well with high and low student performance. Our results show that students who teach and receive metacognitive support exhibit more of the high performing behaviors than the other two groups
