Small group learning is widely advocated in educational institutions around the world and has drawn constant attention in research. Group interaction is a key component of group-based learning. However, its implementation in existing learning practices is inefficient. Previous studies discussed the use of concept mapping in group learning. Concept mapping as an external representation affords a communicative function that triggers shared cognition in collaborative learning. Empirical work reported the pedagogical usefulness of collaborative concept mapping in supporting group learning processes. However, there lacks an effort in systematically examining the effects of collaborative concept mapping in influencing students’ interactional processes according to frame works of group learning activities. This study in the first part examines the effects of collaborative concept mapping on interactional processes at the cognitive, metacognitive, and socio-emotional dimensions in group learning guided by frameworks of group learning activities. An experimental design method (i.e., concept mapping vs. no concept mapping) is used to examine the effects. Beyond, since task condition is a key issue in determining the effectiveness of intervention elements for shaping interaction, and concept mapping is used for pursuing different types of tasks in educational applications, this study takes task condition into account in the experimental design. A salient problem in collaborative use of concept mapping in distance groups is that participants need to put special efforts into coordination of group activities. Prior studies proposed designing roles functioning at different aspects to structure group activities in collaborative concept mapping. Using roles was found to facilitate task-focused and reflective interaction. However, there is a lack of a systematic view in the design of roles to assist interaction considering the multidimensionality of group interaction. There also lacks empirical investigations into the effectiveness of assigning roles in concept mapping mediated group learning. To address these issues, this study in the second part proposes a role-based approach, i.e., assigning the roles including cognitive leader, metacognitive leader, and socio-emotional leader to participants, in collaborative concept mapping to facilitate group learning processes. An experimental study is implemented to evaluate the effectiveness of the intervention. The study finds that concept mapping has different effects on group learning in different task conditions. Concept mapping effectively mediates learning processes and leads to superior task performances for conceptual tasks, while functions deficiently neither in mediating group learning processes nor in producing superior task performances for design tasks. Assigning roles in collaborative concept mapping is evidenced to be feasible and useful in improving socio-emotional experiences in group learning. / published_or_final_version / Education / Doctoral / Doctor of Philosophy