(SUMMARY OF A FULL PAPER)
M. Slater, A. Sadagic, M. Usoh
Department of Computer Science
University College London, UK
School of Technology Management and Economics
Chalmers University, S-412 96 Gothenburg, Sweden
An experiment was designed to explore the behaviour of small groups carrying out a task initially in a virtual and continuing in a real environment. Each of the 10 groups involved consisted of three people, unknown to one another beforehand. The group task consisted of solving a set of riddles. The task only involved observation and talking, and it could be solved most efficiently by group cooperation.
The focus of the study was not at all on performance, in the sense of how well the task was completed, but rather on how the social relations between the members developed in the virtual environment, and how, if at all, these carried over to their interactions in the real world. In particular, the study was concerned with the following issues:
Small group meetings in virtual environments with the people involved continuing the same task in a real environment (of which the virtual was a simulation) have not been studied before. In this experiment there was an attempt to explore the pattern of relationships within the shared VE, and also to see how these changed in continuing real meetings. The work described in this paper nevertheless makes a limited start in this endeavour - limited for two main reasons: first the length of time of the meetings was very short (15 minutes in the virtual followed by 15 minutes in the real). Second, the order in which the meetings occurred (first virtual and then real) requires a control situation where a similar number of groups carry out the experiment first in the real and then continuing in the virtual. This note summarises the study that was carried out.
The study involved 10 groups of three people each recruited by advertisement on the UCL campus. There was no payment for taking part in the study. The experiment took place over a two week period. There were four experimenters involved in the study, one ('minder') each to look after one of the subjects, and a 'floor manager' who maintained overall control and synchronisation of the various activities. The experiment took place in one large laboratory divided into partitions, with the three subjects at opposite sides of the laboratory. Care was taken to avoid the subjects seeing or meeting each other before the start of the experiment. As each subject arrived they were assigned to their 'minder' who took them to their assigned workstation, or in one case to the immersive virtual reality room at one end of the main laboratory. Each subject was assigned a colour (Red, Green or Blue) and they were referred to by that colour throughout the experiment and later de-briefing. The subjects could not see their own avatars (except for the Red, immersed, person if he or she looked downwards).
Each subject was introduced to the system that they would be using. This was either a desktop system (Green and Blue) or an immersive system with a head-mounted display (Red). The virtual environment displayed was actually a rendition of the laboratory in which they were actually physically located. Each was represented by an avatar of the same colour as their assigned name.
Their first task was to individually learn to move through the environment. Then, at a signal from the 'floor manager' each subject was given a sheet describing the overall task to be performed. Then again on a signal they were invited to put on earphones, and to introduce themselves to one another. They could only refer to themselves and to the others by their colour.
The task was to locate a room which had sheets of paper stuck around the walls. The sheets each had several words in a column, each preceded by a number. The words across all sheets with a common number belonged to a 'saying' (for example, 'A critic is a man who knows the way but can't drive a car'). The task was first to figure this out and second to unscramble as many of these sayings as possible. The subjects were asked to find the room with the papers together, and then solve the puzzle. The room with the papers was the rendition of the room with the virtual reality equipment, where the Red subject was physically located.
The Green subject was given an additional task, not revealed to the others. Green was asked to monitor Red as closely as possible, always trying to be in Red's line of vision, although taking part in the puzzle solving task as much as possible. If Red objected Green was to comply temporarily with Red's wishes, but then continue anyway with this monitoring task.
The minders sat unobtrusively near the subject throughout the virtual part of the group activity, in case of problems. The minder of Green had an additional job - to prompt Green to obstruct Red if Green did not appear to be carrying out this task but rather became only involved in the puzzle solving activity. After about 15 minutes the virtual session was terminated, and the subjects completed a questionnaire, which took about 10 minutes. Then each subject was required to put on a waistcoat of their colour, and at a signal from the floor manager, they all met together in real life for the first time just outside the virtual reality room, the room which had the real puzzles placed on the walls.
They were then invited to continue the task in the physical location, which lasted for about another 15 minutes. At the end of that time they completed another questionnaire, and then met with the floor manager for a debriefing. During the virtual session the virtual movements of the subjects were automatically recorded, and an audio tape recorded their conversation. The real session was videotaped from above giving a plan-view.
The Red (immersed) person was using a Silicon Graphics Onyx with twin 196 MHz R10000, Infinite Reality Graphics and 64M main memory, running Irix 6.2. The tracking system has two Polhemus Fastraks, one for the HMD and another for a 5 button 3D mouse. The helmet was a Virtual Research VR4 which has a resolution of 742230 pixels for each eye, 170,660 colour elements and a field-of-view 67 degrees diagonal at 85% overlap. The total scene consisted of about 3500 polygons which ran at a frame rate of no less than 20 Hz in stereo. The latency was approximately 120 ms.
The Red subject moved through the environment in gaze direction at constant velocity by pressing a thumb button on the 3D mouse. There was a virtual body (avatar) which responded to hand and head movements. The Green subject used a SGI High Impact system with 200Mhz R4400 and 64MB main memory. The scene was shown on the full 21 inch screen display. Navigation was accomplished by using the keyboard arrow keys, with up and down arrows giving forward and back movement, and left and right keys providing rotation. All movement was on the horizontal plane of the floor. The Blue subject used an SGI O2 running at 180Mz on Irix 6.3, with an R5000 processor, and 32MB main memory. The scene was shown on a full 17 inch screen display. Navigation was the same as for the SGI Impact.
The sound system used was the Robust-Audio Tool (RAT) v.3.023. This
allows multiple users to talk over the Mbone (Hardman, et. al., 1995).
The virtual reality software used throughout was DIVE 3.2 (Carlsson and
Hagsand, 1993). A DIVE avatar was used for each of the participants,
and was the same for each except for the colour. An image of such an
avatar is shown in Figure 1.
Statistically significant results were:
A major issue explored in the de-briefings was the relationship of the people to their avatars. The most interesting way in which this was realised was through projection - that is, individuals were respectful of the avatars of the other people, and tried to avoid carrying out actions that would cause distress or be impossible in real life.
This process of being mindful of the avatars of others was surprising, they were taken seriously in spite of all their shortcomings. This relationship to the avatars was noticed in another way - the surprise that some people experienced on meeting the real person.
This analysis of the post-experimental group discussion revealed a surprising degree of attachment and relationship towards the virtual bodies (avatars). Although, except by inference, the individuals were not aware of the appearance of their own body, they seemed to generally respect the avatars of others, trying to avoid passing through them, and sometimes apologising when they did so. These were very simple avatars, with limited movement and no capability for any kind of emotional expression. If even these can evoke such responses, it is interesting to wonder what responses more powerful avatar representations might evoke.
This note reports a partial study. More groups must be included, the contact time must be extended, the order of presentation varied (some groups should meet first in the real world and then continue in the VE), the monitoring task or its equivalent in a future study, should be included in both real and virtual parts, and for some groups only in the real part, rather than just the particular configuration used here. Essentially, this study was conducted to find out some of the questions that should be asked in a more thorough and extensive experiment, and the results should be considered in that spirit.
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