Gestures and cooperation: considering non verbal communication in the design of interactive spaces

This dissertation explores the role of gestures in computer supported collaboration. People make extensive use of non-verbal forms of communication when they interact with each other in everyday life: of these, gestures are relatively easy to observe and quantify. However, the role of gestures in human computer interaction so far has been focused mainly on using conventional signs like visible commands, rather than on exploiting all nuances of such natural human skill. We propose a perspective on natural interaction that builds on recent advances in tangible interaction, embodiment and computer supported collaborative work. We consider the social and cognitive aspects of gestures and manipulations to support our claim of a primacy of tangible and multi-touch interfaces, and describe our experiences focused on assessing the suitability of such interface paradigms to traditional application scenarios. We describe our design and prototype of an interactive space for group-work, in which natural interfaces, such as tangible user interfaces and multi-touch screens, are deployed so as to foster and encourage collaboration. We show that these interfaces can lead to an improvement in performances and that such improvements appear related to an increase of the gestures performed by the users. We also describe the progress on the state of the art that have been necessary to implement such tools on commodity hardware and deploy them in a relatively uncontrolled environment. Finally, we discuss our findings and frame them in the broader context of embodied interaction, drawing useful implications for interactions design, with emphasis on how to enhance the activity of people in their workplace, home, school, etc. supported in their individual and collaborative tasks by natural interfaces.