Ever more frequently, social and particularly group interactions, involve mediated communication. Yet we know very little about the factors determining the effectiveness of the interaction. How do participants in mediated communication substitute the implicit, and non verbal signals which play such an important role in traditional, face to face communication? What are the equivalent signals in a mediated environment? The mechanisms involved in traditional communication are well-known. By contrast, very little is known about the forms of mediated communication. For instance, we do not know the role of implicit and non-verbal communication when the communication takes place in a mediated environment. PASION's working hypothesis is that in mediated environments these messages will take completely new forms and that these forms are due to group interactions in technology-mediated environments. As current communication technologies are ineffective in conveying the social, non-verbal a...