Novel 3D displays improve laparoscopic interventions as a result of faster performance and higher precision without causing a higher mental workload. Therefore, they have the potential to significantly impact the further development of minimally invasive surgery. However, as shown by the custom-built 3D mirror display, this effect can be improved, thus stimulating further research.

We conducted two experiments to investigate how stereoscopy and technologies that allow individual eye contact affect the impression of telepresence in video-conferencing. Telepresence is defined as the degree to which participants of a telemeeting get the impression of sharing space with the remote site. Results revealed, among other things, that stereoscopy increases telepresence and makes videoconferencing more attractive. In addition, we found that reduced eye contact angles enhance the recognizability of individually addressed nonverbal signals. However, a setup that eliminates horizontal and vertical eye contact angles seems to be advantageous only in conferences with more than two persons per site.

This paper deals with factors affecting Communicative Presence in videocommunications. Communicative Presence is defined as the capacity of a system to transfer mutual communicative signals of interlocutors. The experiment the paper reports on examined the effects of various features of videoconferencing systems in terms of several aspects, such as the conferees' feeling of being individually addressed by non-verbal signals (e.g. eye-contact), the flow of conversation, user satisfaction, and the willingness to use videoconferencing systems. One system feature that was systematically varied was the degree of vertical and horizontal eye-contact angles. In order to reduce the horizontal eye-contact angles for the two test subjects acting as conferees at one site of the experimental set-up, two different images (one per conferee) which were in accordance with the perspectives the conferees would have in a similar face-to-face meeting were displayed (“view-per-person” principle). Another feature that was examined was the spatial resolution of the displayed images. The results showed that large eye-contact angles as well as a low resolution decrease the feeling of Communicative Presence. Within the framework of the experiment, the hypothesis concerning the benefits of a view-per-person representation could not be verified.

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The paper discusses factors that affect the impression of telepresence in videocommunications. Telepresence is experienced by interlocutors to the extent to which natural visual cues from the remote site are adequately transferred by the medium. The paper reports on two experimental Human Factors studies investigating the effects of various features of videoconferencing systems in terms of, inter alia, the conferees' impression of telepresence as well as user satisfaction and the willingness to use those systems. Within the framework of Experiment 1 the system features that were varied were the scale of representing the conferees (natural vs. reduced size) and the representation of the conferees' surroundings (small vs. large sector of the remote room). In Experiment 2 the system feature being tested was the stereoscopic representation of the conferees. Results showed that both the natural-size representation of conferees as well as the stereoscopic representation increase the impression of telepresence. The expected benefits of a representation of the conferees' surroundings could not be verified. Given a fixed size of the screen, the trade-off between the conferees' size and the representation of surroundings is in favor of the natural size representation.