Various domains require practitioners to encounter and resolve ill-structured problems using collaborative problem-solving. As such, problem-solving is an essential skill that educators must emphasize to prepare learners for practice. One potential way to support problem-solving is through further investigation of instructional design methods that employ case-based reasoning. These learning environments consist of narratives of practitioners as they reason through related ill-structured problems. However, very little research exists about how case libraries impact learning, especially collaborative learning. For this study, 22 participants enrolled in a teacher education program were randomly assigned to two groups as they resolved an ill-structured problem. The results demonstrated that both groups had similar patterns of discussion, but the case library condition collaborated at a higher rate for each of the categories of the content analysis.