User`s guide

picture quality, and typically use a dedicated link so bandwidth isn’t shared with LANs and Internet
connections.
The VideoWindow system (Fish 1990) used a specially-developed camera that captured video
images which were twice as wide as a standard NTSC video image (i.e. 720 × 2 or 1440 pixels). The
resulting aspect ratio is 8:3, compared to the standard 4:3. Movie film and high-definition television
use an aspect ratio of approximately 16:9. A very wide image produces a higher sense of realism
than a standard television image. The VideoWindow’s projected image three feet (91 cm) high by
eight feet (244 cm) wide. The VideoWindow’s images were approximately life-size. Coupled with
the wide-screen image format, the resulting image is quite realistic.
2.4 Problems with Current Systems
Informal communication is frequent, interactive and expressive (Fish et al. , 1993). A later system
developed by Fish et al. (1993) is the Cruiser system. This consisted of a number of nodes (com-
puters) with video display, camera, speakers and microphone. Users could initiate a connection to
any of the other nodes, or let the system choose a node at random. Random calls were not often
answered. On the other hand, users found the system useful to call other people to discuss work, but
usually this was only to schedule face-to-face meetings or for short discussions. When discussions
became sufficiently involved, users met face-to-face.
The users were surveyed, and the main reason behind this was the inability to share work, for
example computer screens or printouts, and the inability to work together — users often stopped
a Cruiser session to use a blackboard or a computer together. Tang (1992) also found that shared
drawing boards were an important part of videoconferencing.
Ishii et al. created a system which combined videoconferencing and a digital drawing board called
ClearBoard (Ishii 1992). This used a mirrored LCD panel which displayed the image of the other
person, and which also could be written on with whiteboard markers. The video image displayed on
the LCD display was overlayed with the drawings from the other person, giving a shared whiteboard.
The analogy used was that users were drawing on a sheet of glass separating them, with the difference
that the drawing was shown mirrored correctly (i.e. the image was flipped horizontally when sent, so
that a mirror image is not seen by the other user). The main problem users found with the system
was that they could not erase their partner’s drawings.
Videoconferencing is used for both formal and informal communication (Fish 1993). Formal
communication includes scheduled meetings, conferences and seminars. Informal communication
includes unscheduled meetings and personal conversations. Informal communication is useful in
solving problems, generating ideas and helps people get to know each other. Informal communi-
cation is more difficult when the people communicating are on different locations (Sellen 1992).
Videoconferencing is ideal in these circumstances.
Takao and Innami (1998) showed that desktop videoconferencing systems improved the quality
of group decisions. They compared the results of solving a standard problem in a face-to-face
meeting, a videoconferencing system where only the speaker is shown, and a videoconferencing
system in which all members of the group are shown. There was little difference in the results for
the speaker-only system compared with the face-to-face system, but a significant difference between
the all-member system and the face-to-face system. Preliminary research ascribes the differences as
due to reduced eye contact with each person, no distinction of status among the people in the group,
and no recognition of physical difference, such as height, among participants.
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