Proceedings of the Annual Meeting of the Cognitive Science Society

Our goal is to develop a tutoring system, called CATO, that teaches law students skills of making arguments with cases. CATO's domain model provides a plausible account of legal arguments with cases, but is limited in that it does not repre?sent certain background knowledge. It is important, however, that students leam to apply and integrate this background knowledge when making arguments with cases. Given that modeling this background knowledge is difficult in an ill?stiuctured domain like legal reasoning, it is worth exploring how effectively one can teach with a model that represents ar?gument structure but relatively little background knowledge. The CATO instructional envirormient, comprising a case da?tabase and retrieval tools, enables students to apply the CATO model to a specific problem. In a formative evaluation study with 17 beginning law students, we compared instruction with the CATO environment, under the guidance of a human tutor, against more traditional classroom instruction not based on the CATO model. W e found that human-led instruction with CATO is as good as, but not better than, classroom instruction. How?ever, answers generated by the CATO program received higher grades than the students' answers, suggesting that the model can potentially be employed to teach even more effectively. Examples drawn fitom protocols show that students were able to use the CATO model flexibly and integrate background knowledge appropriately, at least when guided by a human tu?tor.