International audienceMulti-user multimodal interactive systems involve multiple users that can use multiple interaction modalities. Although multi-user multimodal systems are becoming more prevalent (especially multimodal systems involving multitouch surfaces), their design is still ad-hoc without properly keeping track of the design process. Addressing this issue of lack of design tools for multi-user multimodal systems, we present the COMM (Collaborative and MultiModal) notation and its on-line editor for specifying multi-user multimodal interactive systems. Extending the CTT notation, the salient features of the COMM notation include the concepts of interactive role and modal task as well as a refinement of the temporal operators applied to tasks using the Allen relationships. A multimodal military command post for the control of unmanned aerial vehicles (UAV) by two operators is used to illustrate the discussion
