The authors work as online tutors for a BSc (Hons) physiotherapy programme at Coventry University in the United Kingdom. This paper represents a stage in our developing understanding, over a 3 year period, of the impact of group dynamics on online interaction among physiotherapy students engaged in sharing with their peers their first experiences of clinical practice. The literature exploring online interaction tends to situate meaning either in theories borrowed from conventional face-to-face interaction or on virtual interaction. Research focusing on "blended learning" that combines face-to-face and online interaction is limited in terms of considering how group dynamics impact groups that are constituted and reconstituted in the two very different learning contexts. Using a case study approach, the authors consider how group dynamics change as groups move from face-to-face to online collaboration in pursuit of learning objectives. We characterize typical features of the cases and draw conclusions based on similarities and differences. Findings suggest that group learning is linked to group cohesion, which appears to be mediated by social and cognitive factors that students bring with them. Social presence appears vital to positive group dynamics and is a precursor to cognitive presence, which develops when groups rise above their desire to be sociable and supportive. Group dynamics, whether positive or negative, and their consequent impact on interaction appear to be relatively stable across contexts once the group scene is set through face-to-face interaction. Engagement and interaction of individual students, however, can alter when face-to-face interaction moves online.