there is lack of understanding of how members prefer to organize and represent the shared rationales. In this paper, I report a classroom study about how group learners used a shared rationale space to articulate and share their rationales. The findings of the investigation show that: group members would brainstorm the ideas and generate rationales to justify the ideas before reading the others' ideas and rationales; the members in general brainstormed all the ideas first and then elaborated the rationales to justify the ideas; and the members grouped the shared rationales according to their authors. These findings suggest that the WYSIWIS model is not applicable to support rationale articulation and generation in a virtual group workspace. Instead, an adaptive intelligent group user interface is needed to facilitate the involved associative thinking and deeper thinking processes.