Amela Sadagic

Small-Group Behavior in a Virtual and Real Environment: A Comparative Study

This paper describes an experiment that compares behavior in small groups when its members carry out a task in a virtual environment (VE) and then continue the same task in a similar, real-world environment. The purpose of the experiment was not to examine task performance, but to compare various aspects of the social relations among the group members in the two environments. Ten groups of three people each, who had never met before, met first in a shared VE and carried out a task that required the identification and solution of puzzles that were presented on pieces of paper displayed around the walls of a room. The puzzle involved identifying that the same-numbered words across all the pieces of paper formed a riddle or saying. The group continued this task for fifteen minutes, and then stopped to answer a questionnaire. The group then reconvened in the real world and continued the same task. The experiment also required one of the group members to continually monitor a particular one of the others in order to examine whether social discomfort could be generated within a VE. In each group, there was one immersed person with a head-mounted display and head-tracking and two non-immersed people who experienced the environment on a workstation display. The results suggest that the immersed person tended to emerge as the leader in the virtual group, but not in the real meeting. Group accord tended to be higher in the real meeting than in the virtual meeting. Socially conditioned responses such as embarrassment could be generated in the virtual meeting, even though the individuals were presented to one another by very simple avatars. The study also found a positive relationship between presence of being in a place and copresencethe sense of being with the other people. Accord in the group increased with presence, the performance of the group, and the presence of women in the group. The study is seen as part of a much larger planned study, for which this experiment was used to begin to understand the issues involved in comparing real and virtual meetings.

Small group behaviour experiments in the Coven project

The Collaborative Virtual Environments (Coven) project, a four-year European project launched in October 1995, designs and explores collaborative virtual environment (CVE) technology. It aims to investigate the feasibility of scalable CVE worlds through developing CVE systems and demonstrating prototype applications in a virtual travel rehearsal scenario. Our experiments in collaborative virtual environments investigated group behavior issues such as relationships between emergent leadership and computational resources, and the sense of presence and copresence among participants.

Dynamic polygon visibility ordering for head-slaved viewing in virtual environments

This paper presents an approach to visibility called the Viewpoint Movement Space (VpMS) algorithm which supports the concept of dynamic polygon visibility orderings for head‐slaved viewing in virtual environments (VE). The central idea of the approach is that the visibility, in terms of back‐to‐front polygon visibility ordering, does not change dramatically as the viewpoint moves. Moreover, it is possible to construct a partition of the space into cells, where for each cell the ordering is invariant. As the viewpoint moves across a cell boundary typically only a small and predictable change is made to the visibility ordering. The cost to perform this operation represents a notable reduction when compared with the cost of resolving the visibility information from the BSP tree where the classification of the viewpoint with every node plane has to be performed. The paper demonstrates how the subdivision into such cells can represent the basic source for an acceleration of the rendering process. We also discuss how the same supportive data structure can be exploited to solve other tasks in the graphics pipeline.