This study describes the result of implementing the Problem List Generator (PLG), a computer-based tool designed to help veterinary students learn diagnostic problem solving in clinical pathology. Participants included 421 veterinary students. The comparison group of 334 students did not use the PLG at all, one experimental group participated in PLG-based case-discussion sessions, and the other used the PLG for case-discussion sessions and for homework. Both treatment groups scored significantly better on the final exam (p = .001 and .000 respectively) than the comparison group. The findings suggest that providing an expert problem solving process to students, and ensuring that both students and teachers use the same format for representing the problem space, improves student problem solving ability.