This research investigated how differently elementary school students participate in synchronous online collaborative learning by analysing their discussions with their partners. Two hundred and seventy-eight Taiwanese students, ranging in age from 11 to 12 years old, were involved in this study. The students were randomly arranged within-class into three-member groups. Each group used a collaborative learning system to discuss and accomplish a group assignment (creating a shared concept map). The textual discussions by each individual student were collected, categorised and accumulated. Cluster analysis was adopted to statistically classify students based on their discussion characteristics. We found that a student, while participating in online collaboration and communication, exhibited a distinct style: "less contributing," "coordination emphasising," "communicative" or "task-oriented." In addition, students exhibiting the "task-oriented" pattern and students predominantly showing "communicative" behaviours were found to have better learning performance and retain more knowledge than students observed to be "coordination emphasising" or "less contributing" within group collaboration. (Contains 3 tables and 2 figures.)