Analysing Interaction: A comparison of 2D and 3D techniques

Human interaction is inherently three dimensional and multi-party. The human body is 3D, performing actions within a 3D space. 3D aspects of communication such as the orientation and spatial arrangement of participants, collaborative gestures and synchrony are central to how communicative signals are formed and interpreted within an interaction. Traditional interaction research has relied on 2D audio-visual techniques to record interaction, however a comprehensive analysis of the 3D aspects which guide the interpretation and formation of interaction cannot be conducted by viewing interaction on a 2D plane. An emerging alternative to the traditional 2D techniques is the use of 3D motion capture technology. Although this technology has had extensive use within the film industry, few studies have used motion capture as a tool for examining interaction. This paper provides a comparative account of 3D motion capture techniques and traditional 2D audio-visual techniques for analysing interaction using data from a pilot study. The merits of 3D techniques are demonstrated. The potential of 3D motion capture technology to enhance and build upon previous studies within the field of human interaction is discussed and we present one example of an application area. 1