Non-participants joining in an interaction in shared work spaces: Multimodal practices to enter the floor and account for it

This article studies how co-present workers can join in a co-present interaction they were not previously involved in, thus challenging initial participants' interactional preserve. It is based on ethnographically-informed analyses of video-recorded interactions in workplaces, in English as a lingua franca and in French. Potential joiners' recurrent embodied and verbal practices are identified and analyzed, showing regular methods associated with potential joiners' position relative to the F-formation, and different layouts typical of workplaces. Another set of findings bears on how potential joiners shape their move so as to account for joining in at that moment, to project a more or less extended participation, and to implement a collaborative project. Beyond the variety of projects the practice can serve, potential joiners' moves are systematically designed so as to demonstrate their contribution to the progression of work.