from the users world - has been realized by a few projects either with video based techniques ( Hoch 1997) or with tracking devices like the data glove ( Latoschik 1998, LaViola 1999). In all of these projects the user stands in front of a large scale back projection display. Hoch uses deictic gestures in combination with simple speech commands like put this there to build a tool for scenery design. The features that are calculated from video images are projected onto a simple human body model to get the 31) pointing direction. La Viola presents a tool for scientific visualization that can be controlled by 3D semantic and deictic gestures and simple speech commands.
From the results of his Glow Flow project, Myron Krueger concludes: ,,So that it can respond intelligently, the computer should perceive as much as possible about the participants' behavior" ( Krueger 1991). Gesture as a means of nonverbal communication consists of more than a hand posture and a hand movement. Cuxac explained that a sentence in French sign language can have different meanings depending on the direction and the place relative to the upper body where the gesture is performed ( Cuxac 1999). Additionally, the term gesture bears itself different kinds of human motions e.g. gaze, miming, movements of the head or limbs, movements of the whole person. To build a real humanlike communication between humans and computers it is necessary to create so-called responsive environments that are aware of the users mood and react or act intelligently. First attempts to incorporate the user's movements in a responsive environment were undertaken in the PsychicSpace project ( Krueger 1991) and in the German Dialogue with Knowbotic South project ( Knowbotic Research 1997). In both projects, the position of the user is tracked either by a tracking device or with a video camera to navigate in a virtual data space. The data space is presented by visual and audio feedback and changes with each body movement.
What has been illustrated, is that gesture based input offer new and challenging ways of interaction. If combined with speech, they open a new dimension towards the naturalness of human-computer interaction.
Adams, D. ( 1979). The Hitchhiker's Guide to the Galaxy. Ballantine Books, November 1995: reissued edition.
Bekiaris, E., Machate, J. & Burmester, M. ( 1997). Towards an intelligent multimodal and multimedia user interface providing a new dimension of natural HMI in the teleoperation of all home appliances by E&D users. La Lettre de l'IA, Proceedings of Interfaces 97