The effect of case nodes in problem-based learning on the length and quality of discussion: a 2x2 factorial study.

Background: Problem-based learning (PBL) relies heavily on case structure for their success. To make more meaningful cases, faculty introduced a "case node" that requires students to make a group decision on the action they will take at a given point in the case. The purpose of this study was to determine whether case nodes enhance PBL discussions.