This study is a third in a series of studies that examined students' information seeking and problem solving behaviors while interacting with one of two types of web-based representations of an ill-structured instructional design case: hierarchical (tree-like) and heterarchical (network-like). A Java program was used to track students' hypermedia journeys and decision-making patterns through the case designs. Additionally, student teams submitted case solutions and engaged in inter-team online discourse to critique case solutions. Data from the tracking program, case solutions, and online discourse were analyzed to determine the effects of hierarchical versus heterarchical case designs on information seeking and problem solving behaviors. (Contains 4 tables and 6 figures.)