Self-managed learning groups are regularly used in higher education. However, there is little direct evidence as to strategies that can enhance their efficacy, or the factors that influence students' engagement with the process of self-management. If students are expected to manage their out-of-class collaborative learning experiences, then educators need a better understanding of the social influences on students' process choices and use of developmental activities. This study investigated the experiences and perceptions of 152 students who were members of self-managed learning groups. Participation in a formative team-building activity and a greater frequency of meetings were found to predict perceptions of group effectiveness. Students identified a range of factors (related to themes of risk/safety and development/compliance) that influenced their engagement in developmental activities. Findings are discussed in terms of learning frameworks and implications for self-managed learning group design. (Contains 5 tables.)