Multi-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.

In this paper we focus on the software design of a multimodal driving simulator that is based on both multimodal driver's focus of attention detection as well as driver's fatigue state detection and prediction. Capturing and interpreting the driver's focus of attention and fatigue state is based on video data (e.g., facial expression, head movement, eye tracking). While the input multimodal interface relies on passive modalities only (also called attentive user interface), the output multimodal user interface includes several active output modalities for presenting alert messages including graphics and text on a mini-screen and in the windshield, sounds, speech and vibration (vibration wheel). Active input modalities are added in the meta-User Interface to let the user dynamically select the output modalities. The driving simulator is used as a case study for studying its software architecture based on multimodal signal processing and multimodal interaction components considering two software platforms, OpenInterface and ICARE.

Interactive systems including multiple interaction devices and surfaces for supporting the collaboration of a group of co-located users are increasingly common in various domains. Nevertheless few collaborative and multimodal interface specification notations are proposed. As a first step towards a notation for specifying a design solution prior to its software design and development, we adopt an empirical approach. We applied and compared four existing notations for collaborative systems by considering a case study, namely, a system for supporting informal co-located collaboration in hospital work. This paper reports the conclusions from this empirical comparison.