Computer tutors can address students learning to solve complex engineering problems

The ability to solve complex problems in which considerable latitude in solution is allowed is an important goal in engineering education. While feedback is critical to learning, traditional grading of handwritten homework rarely provides effective, timely feedback on attempts to solve complex problems. To address the research question of whether automated feedback can be provided on complex problem solving, a cognitive tutor approach is pursued, with truss problems in statics used as a test case. The tutor maintains a cognitive model of problem solving of the class of problems, and associates various solution steps with distinct skills or knowledge components. One can determine whether students learn individual skills by measuring the error rate as a function of practice. Data was obtained from students using the tutor to solve truss problems in place of the weekly homework assignment. Statistical analyses of the data showed that distinct skills involved very different error rates, justifying tracking them separately. Furthermore, for most skills, the error rate either was low from the start or decreased with practice, providing evidence that feedback improved performance.