Large-scale, group-to-group collaboration is an emerging trend, yet has so far not received much attention. We performed an ethnographic study to examine how interaction and perception differ between collocated and distributed interaction. We studied a large-scale space mission design team composed of collocated teams distributed at three different sites. We discovered that subgroup interaction occurred very differently within sites compared to across sites, which impacted negotiation and information seeking. We also found that the distributed team could successfully create new common terms and methodologies, but failed to adopt them. Last, we found a number of misattributions that occurred in the distributed interaction, i.e. beliefs that the technology is conveying one’s actions across distance as they believe that others locally would perceive them. We discuss how such differences in distributed collaboration can lead to risk in design and how technology can better support large-...