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The VideoWindow System in Informal
Communications
Robert S. Fish
Robert E. Kraut
Barbara L. Chalfonte
Bellcore
445
South Street
Morristown, NJ 07962-1910
INTRODUCTION
Imagine sitting in your work place lounge having coffee with some colleagues. Now
imagine that you and your colleagues are still in the same room, but are separated by a
large sheet of glass that does not interfere with your ability to carry on a clear, two-way
conversation. Finally, imagine that you have split the room into two parts and moved
one part 50 miles down the road, without impairing the quality of your interaction with
your friends. That scenario illustrates the goal of the VideoWindow system project: to
extend a shared space over considerable distance without impairing the quality of the
interactions among users or requiring any special actions to establish a conversation.
While the VideoWindow system -- a very large screen, full duplex teleconferencing
technology that we will describe later in this paper -- cannot yet achieve this goal, we
believe it can come closer to it than any other system yet invented.
The VideoWindow system project at Bellcore has its roots in two related lines of inquiry.
One is our interest in informal communications as a mechanism for coordinating the
social and production roles of people in the workplace. Our belief is that informal
communication is of crucial importance in the workplace, but that physical proximity is
currently the only technology that adequately supports it. Since telecommunications
(literally, communications from afar) is by nature a substitute for physical proximity, it
seems appropriate that there be telecommunication technologies for supporting informal
communications. However, in looking at the contrast between formal and informal
communication, it occurred to us that the more spontaneous and informal communication
was, the less well it was supported by telecommunication technology. We realized that
we had well established procedures for scheduling meetings and writing reports but little
technology to support bumping into a colleague in the coffee room. Hence, our interest
was drawn towards understanding more about the nature and value of informal and
spontaneous communicative activity and towards seeing whether technology could be
fruitfully employed to aid it.
The second source of the VideoWindow system project is prior experience with audio-
video telecommunications. The history of video as a communications technology has
been a mixed one, showing great successes as a method of broadcasting entertainment, a
mixed record as a method of educational distribution, and a dismal record as a mechanism
for interpersonal communication. The lack of market success for such items as video
telephones and video conferencing systems seems to contradict our intuitions about the
value of visual contact in interpersonal communications. These marketplace approaches
have been geared primarily towards relatively formal communication occasions.
CSCW 90 Proceedings October
1990
Recently, however, several research groups have published reports that explored new
approaches toward video in interpersonal communications [Gale89, Good87, Krau90,
Root881. In our case, we began to explore whether video’s employment in systems for
informal communication might be successful because video simultaneously reminds you
of a need to talk to someone and provides a communication channel through which to
carry on the conversation. This lead us to think that it might become t& technology to
support spontaneous, informal communication. The following sections in this paper
describe in more detail the nature of informal communication, describe some of the
features new technology must borrow from physical proximity to support it, describe the
VideoWindow system for supporting informal communications, and then describe the
results of a 3 month trial experiment of the VideoWindow system in our laboratory.
THE NATURE OF INFORMAL COMMUNICATION
Figure 1 illustrates several of the variables that we think distinguish formal from
informal communication. At the heart of what we term informal communication is its
ad lib nature. Conversations take place at the time, with the participants, and about the
topics at hand. None of these characteristics - timing, participants, or agenda - is
scheduled in advance. Moreover, during its course the communication changes to take
into account the participants’ current interests and understandings. In this sense, informal
communication is truly interactive with each participant in the communication being able
to respond to what they perceive to be the current state of affairs, including the
communication up until that point and their perception of the other participants’ reactions
to the communication up until that point. Through this feedback mechanism, informal
communications can be more effective than formal ones as participants in the
conversations elaborate or modify what they have to say to deal with someone else’s
objections or misunderstandings, e.g., [Krau82].
Formal Informal
l
Scheduled in advance
l
Unscheduled
l
Arranged participants . Random participants
l
Preset agenda * Unarranged agenda
l
One-way
l
Interactive
. Impoverished content 4 Rich content
@ Formal language &
l
Informal language
speech register & speech register
Figure 1. The formality of communication
Our distinction between formd and informaJ communication parallels Daft and Lengel’s
[Daft841 distinction between impoverished and rich communication channels. We add to
their criteria of bandwidth and interactivity, the additional criterion of spontaneity.
According to Daft and Lengel [Daft86], rich communication channels are ones that “can
overcome different frames of reference or clarify ambiguous issues to change
understanding in a timely manner” (p. 560). In order of decreasing richness, they consider
(1) face-to-face, (2) telephone, (3) personal documents such as letters, (4) impersonal
documents, and (5) numeric documents. (See also [Stoh87] for further discussion of the
formal-informal distinction.)
CSCW 90 Proceedings October 1990
2
In a careful analysis of episodes of spontaneous, informal interaction EKrau901, we found
several common features that should inform our investigations of technology to support
informal communications. First, all the episodes we examined were unplanned and
unanticipated. The participants all engaged in more or less useful conversation but did
not know they would be having them even seconds before they occurred. Second, the
visual channel was a prerequisite for these interactions to occur. In these cases, the visual
channel was instrumental in identifying a partner for conversation, in identifying the
precise moment when the potential conversational partner was available, and in
establishing a topic for the conversations. In each case, the initiator of the conversation
saw and recognized a potential partner whom he already knew before engaging in
conversation. As Kendon and Ferber [Kend73] describe it, sighting is a necessary pre-
interaction phase of a greeting. Seeing someone often brings with it a social obligation
to acknowledge their presence with a greeting. In addition, the visual channel is used to
establish the opportunity for conversation. That is, by looking at a potential target of
conversation, the initiator can often interpret the target’s locus of attention and infer
whether and when he or she is available for conversation. In one example, the initiator
could tell by looking at another person when the target had disengaged from his previous
conversation and was available to be hailed. Potential conversationalists often use the
visual channel to synchronize their behaviors [cf, Kend73] to make sure that they have a
clear channel between them. Finally, seeing someone serves as a potent stimulus to
evoke topics of conversation. Thus the visual channel is often instrumental in
establishing topics of conversation.
In the informal conversations we examined, both production and social work were often
accomplished. While one might characterize a conversation as having a main purpose,
the production and social goals frequently co-occur, and whether a conversation is work-
related or social is a matter of degree. Sometimes a conversation is directly related to
production. In looking at one episode it was clear that the participants were coordinating
their work, updating each other on the status of their project, and attempting to solve a
minor problem impeding progress. Yet it is clear, from the smiles and positive affect
displayed, that the participants were enjoying each other’s company as well. Even when
a conversation is basically social, members of an organization use it to establish and
reaffirm bonds to each other that will underlie later work activity. Many times
conversations and observations supported by informal communication do not support
work immediately at hand. Even these, though, often provide background information
that might potentially be useful for completing a work assignment or for acquiring more
general organizational competence.
TECHNOLOGY FOR INFORMAL COMMUNICATION
In the cases we analyzed, physical proximity was the technology that allowed informal
communication to occur. However, in many circumstances close physical proximity for
a working group cannot be realized. The realities of organizations may preclude
individuals who are supposed to be working together from having their offices near each
other. For example, communities of scientists are often distributed across the nation or
world. In addition, in industry many projects, such as software development, are often so
large that physical proximity for the entire staff becomes a topological impossibility.
With this in mind, techniques for creating artificial proximity through the use of
technology become attractive. However, what characteristics of physical proximity
should be preserved in the artificial proximity that we would like to create?
A concentration
of
suitable partners: Any system that wishes to support informal
interaction must provide access to a suitable population of others. In the physical world
concentration is accomplished by putting people who need to communicate close
together. In the telecommunications domain, everyone who is connected to a common
network is in some sense equally accessible, absent the constraints of distance-sensitive
CSCW 90 Proceedings October 1990
3
charges and lost phone numbers. Thus, as long as a sufficient proportion of the relevant
population is connected, a population of suitable partners is also available [cf Mark87].
CSCW 90 Proceedings
Yet, because everyone is equally accessible - friends and strangers, similar and dissimilar
people - the availability of suitable partners may be too diffuse to create an effective
community for informal interaction. Dialing a phone number at random or posting a
message to a nation-wide electronic bulletin board is unlikely to put the initiator in touch
with an appropriate conversational partner. The requirement for a telecommunications
system to support informal interaction is to concentrate suitable partners.
Co-presence:
For informal interaction to occur, people need an environmental mechanism
that brings them together; they need to be at the same place at the same time. In the
physical world, this mechanism can be a lunchroom, coffee lounge, or other space where
people convene or it can involve the complexity of movement around a work place.
R&D laboratories, in our experience, are places where people are constantly moving
around. Yet much information technology, such as electronic libraries and databases,
reduces the need to move about in order to get work done and therefore reduces the
opportunities for casual interaction [Krau89]. Similarly, separating people (into branch
locations, for example) reduces the likelihood that they will occupy a common physical
space, thereby reducing the likelihood of informal interactions as well.
The essence of telecommunications is co-presence without physical proximity. While
most telecommunications assumes intentional action to initiate communication with a
particular other, it is possible to devise other idioms for non-intentional
telecommunications. Electronic bulletin boards, in which readers come across the
postings of other users of the bulletin board, is one such example.
Low personal
cost: The cost of communication, in terms of the amount of effort needed
to initiate and conduct a conversation, is very low in casual encounters. Often the contact
is a side effect of other activities and as such, the creation of opportunities for
communication involves no extra cost. To provide this low cost communication when
people are dispersed, we need to make getting in touch with one another as easy as
bumping into them in the hallway. The behavioral costs of accessing a communications
system and getting in touch with a desired other party is an important determinant of that
system’s usefulness. If the costs of using a communication source are too high, e.g.,
[Cull83], as is the case with many of the “traditional” teleconferencing systems [Egid90],
the user will be either unable or unwilling to use that system for the brief, frequent,
spontaneous conversations that are characteristic of informal communications.
Visual channel:
The visual channel plays an important role in informal communication.
As we discussed previously, seeing someone can serve several purposes. It provides a
means for recognizing the presence of another person, determining who they, and
assessing their availability for interaction. It also serves as a stimulus for picking a topic
of conversation - seeing someone can remind you that there is something you wanted to
speak to this person about. Finally, the visual with the audio channel provides a medium
to actually accomplish the conversation. A technology for informal interaction must
support both audio and video communications if we are to successfully stimulate
proximity.
THE VIDEOWINDOW TELECONFERENCING SYSTEM
Technical Description
The VideoWindow system [Be1189, Judd891 integrates a very high aspect ratio video
channel with full-duplex multichannel audio. Figure 2 illustrates the VideoWindow
system in use. The video subsystem makes use of a specially fabricated camera that
October 1990
4
produces an image that is twice as wide as that produced by a standard NTSC camera.
This results in an aspect ration of 8 to 3 for the VideoWindow system. For purposes of
comparison, we should note that a standard NTSC camera produces an image with an
aspect ratio of 4:3, the proposed High Definition Television (HDTV) standard uses 16:9,
and the average movie film is about 2:l. Thus, a very wide image is produced
that can
convey a heightened sense of realism compared to a traditional television image. In use,
the VideoWindow system screen is 3 feet high by 8 feet wide and produces images that are
approximately life-size.
Figure 2. The VideoWindow teleconferencing system.
The audio subsystem of the VideoWindow system provides four independent channels that
are arranged so that the spatial localization of speakers and other sounds across the plane
of the VideoWindow system is maintained. The channels am full duplex so that speakers
at both ends of a connection can speak simultaneously just as they would in the normal
ebb and flow of conversation. This contrasts with the audio arrangements used in standard
teleconferencing setups in which audio switching arrangements are used SO that only one
person at a time can speak. Equalizers, highly directional microphones, and some signal
processing techniques are used to prevent ringing and auditory feedback.
In use, the VideoWindow system is configured with a very simple human interface. If
someone at one end of the link sees someone at the other end, they simply have to speak
and they will be heard at the other end. The high visual aspect ratio of the system allows
a broad area to be visible, with people appearing about the same size they would be if
they were located across a modest sized room. The sound localization makes it seem that
the speaker’s voice originates from the location of the speaker’s image. At first glance,
the VideoWindow system offers a very powerful sense of shared space and presence at very
low behavioral cost to the user.
The VideoWindow System Experiment
To look more closely at the effects of the VideoWindow system on informal
communication, we conducted a three month trial in our laboratory. The experiment was
CSCW 90 Proceedings October 1990
set up so that the four characteristics of proximity mentioned above were incorporated
into the experimental setup. The VideoWindow system itself, set up in two commons
areas on different floors of a building, provided the visual channel. It was left on 24
hours a day, 7 days a week and could be used by simply speaking to someone spotted at
the other end. This minimal interface arrangement minimized the personal cost of using
the technology. In order to assure some co-presence of users, free coffee was provided in
the area visible to the window and a group of about 50 people volunteered to have their
mailboxes moved so that they would pick up their mail in the vicinity of the
VideoWindow system. The actual locations of the VideoWindow system were chosen so
that groups of researchers with complementary interests were located nearby. This was
done to increase the probability that suitable conversational partners would be available in
the neighborhood of the VideoWindow system.
Over the course of the experiment, participants were questioned about their use of the
system, their knowledge of other participants both local and remote, and their feelings
about the technology. Video records were kept both of face-to-face interactions in the
lounge areas and interactions that took place over the VideoWindow system.
Results
Two types of data were examined. First, on an episode by episode basis we examined the
individual communication transactions that were recorded on videotape. During the course
of the experiment about 160 hours of videotape were recorded, but for purposes of
analysis, this was condensed to about 24 hours of tape that represented actual
communication opportunities (i.e., at least two people located either in the same room or
on opposite sides of the VideoWindow system). Second, we also examined questionnaire
data from the users of the system in order to see the overall effects that the presence of the
VideoWindow system had on the familiarity and liking that researchers had of each other
and of each other’s work. Users also told us their likes and dislikes about the system and
its features.
Transparency:
In our view, the overall usage of the VideoWindow system should be related to its
transparency. This can be defined as the ability to distinguish interactions that take place
using it from those that occur face to face. If we compare the conversion of
conversational opportunities into actual conversations across the VideoWindow system to
the conversion of face-to-face opportunities taking place in the rooms at either end of the
VideoWindow system, we should get some idea of the relative transparency of the system.
Over the course of the experiment we observed a total of 676 instances in which at least
one person was present at each end of the VideoWindow system (398 cases of exactly two
people, 278 cases of more than two people). Each instance represented an opportunity for
people to strike up a conversation across the VideoWindow system link. On 116
occasions these opportunities were actually converted into verbal interaction, either a
greeting or a conversation. The average conversion ratio was thus 17%: 10% of the two-
person opportunities and 27% of the three-or-more person opportunities were used for
interaction.
Looking at the videotapes of these interactions across the VideoWindow system suggests
that in some cases the system was a transparent medium. Many interactions that took
place via the window seemed indistinguishable from similar face-to-face interactions and
were unlikely to have occurred had the system not been in place. People often spoke and
acted in a fashion that, at least superficially, seemed altered in only minor ways by the
technology. We witnessed greetings, extended social conversation, work coordination,
and the discussion of new research ideas across the VideoWindow system. People tended
CSCW 90 Proceedings October 1990
to speak a little louder and often embedded a discussion of the VideoWindow system itself
in their discussion.
Yet the conversion ratio across the VideoWindow system was substantially lower than the
conversion ratio for face-to-face opportunities. For this comparison, we examined 106
cases in which people were together on a single side of the VideoWindow system and
were thus in the same room, We used this sample to estimate the proportion of face-to-
face conversations that were already in progress prior to entering the VideoWindow
system room. We found that about 36% (with a standard error of 4.6%) of face to face
conversations from this sample were already in progress. Table 1 compares the relative
proportions of conversational opportunities that were converted to some form of
conversation for face-to-face conversations (corrected for conversations already in progress)
and for the VideoWindow system data mentioned above. Table 1 shows that 4 1% of face-
to-face opportunities were converted to interaction. This is almost two and a half times
the conversion rate for the VideoWindow system.
Number of People Present
2 >2 All
VideoWindow 10% 27% 17%
(398) (278) (676)
Face to Face gi) gt) ;tE,
Note : Number represents the corrected percentage of conversational opportunities that
were converted to actual conversations for VideoWindow and Face-to-Face opportunities.
The correction was needed to remove conversations already in progress from the total
Face-to-Face opportunities. Below each percentage is the n or corrected n on which these
proportions are based.
Table 1. Percentage of opportunities resulting in conversation.
Reciprocity:
This version of the VideoWindow system had some properties that worked against the
initiation and maintenance of informal interactions. At the heart of these problems is the
property of reciprocity. In face to face interaction one of the cardinal assumptions is that
if you can see someone else, they can see you and that if you can hear someone else, they
can hear you. These commutative properties are not preserved by the technology of the
VideoWindow system and this leads to some inappropriate behavior on the part of users.
For instance, about 18% of cases in which people failed to convert an opportunity for
conversation into an actual conversation could be attributed directly to reciprocity
problems caused by camera and microphone placement. For example, people often tried
to strike up a conversation when they were too close to the VideoWindow system. This
caused their head to be out of the picture, so they could not be recognized, and put them
out of microphone range, so they could not be heard. Another problem is that it is easy
for people to stand
out
of camera range where they could see the image in the
VideoWindow system but not be Seen by people at the other end. (See the man at the left
edge of Figure 2 who can see others in the VideoWindow system, but cannot be seen by
them.) This contrasts with face-to-face interaction, where covert observation rarely occurs
and requires extra effort on the observer’s part. Solving these sorts of problems requires
rethinking how video cameras and monitors are designed and placed in personal
communications systems.
CSCW 90 Proceedings October 1990
Privacy:
Once a conversation was initiated, conversations over the VideoWindow system
sometimes broke down. One problem was that the VideoWindow system made it difficult
to establish private conversations in otherwise public areas. In fact, the ability to make a
conversation private was one of the most frequently requested improvements mentioned
by users in our sample. When people in a conventional meeting room wish to exchange
private information, they simply move closer together and lower their voices. This
capability is not supported by the VideoWindow system or any teleconferencing systems
designed to link public areas together with hands-free audio. Teleconferencing technology
is optimized to allow several people to converse clearly at the same time. The case of
private conversations illustrates a more general point: technology-mediated systems do
not currently have the communications flexibility and ability to manipuiate media
characteristics that we take for granted in face-to-face conversations.
Architectural and Environmental Context :
Another class of problems stems from the architectural and environmental context in
which the VideoWindow system was situated. A VideoWindow system installation
requires that users go to the room or space in which it is installed in order to use it. This
imposes a moderate behavioral cost on the user to access the technology, unless they are
already using the public space. The centralized nature of the VideoWindow system also
results in a sampling problem: potential encounters are limited to the set of people who
occupy VideoWindow system’s extended space at the same time. People are more likely,
on average, to be someplace other than where. the VideoWindow system is. In addition,
the probability of being acquainted with persons at the other end may be low, given the
small scope of familiarity with people at remote locations. Even within a single building,
a person is less than half as likely to know a person whose primary location is on an
adjacent floor than on his or her own floor IFest50,
Krau90].
Social and Organizational Context :
Although the VideoWindow system can support informal interaction at a distance, its use
requires careful attention to social detail. Thus one could imagine connecting the
cafeterias of two research organizations whose members already know each other and who
have reason to work together. In other circumstances - where the VideoWindow system
connects strangers and where people occupy the VideoWindow system locations
infrequently - the probability of encountering an suitable partner and striking up a
conversation are low. So, even though VideoWindow system may extend the boundaries
of one’s physical space and increase the absolute number of people with whom one can
interact, it does not necessarily extend the effective work space or the social environment
in which people work and in which informal conversations take place.
Conversational Regulation:
As has often been pointed out, [Kend73, Goods], Sche81J the dynamics of starting and
maintaining a conversation are complex and subtle. Humans have developed an elaborate
set of mechanisms that allows them to regulate social interaction. These include
mechanisms for welcoming, allowing, or discouraging others from engaging oneself in
interaction through the
use
of gaze direction, body positioning, gesture, verbal signals,
and the like. However, it is not clear that these mechanisms for conversational regulation
will work as well when they are used in the context of the VideoWindow system. For
example, eye contact and eye aversion are a Frequent concomitant of the decision to start
or not to start a conversation. The use of the VideoWindow system often leads to
anomalies in apparent eye contact that do not occur when people are face-to-face. This is
because the combination of mobile users and cameras with a fixed point of view
CSCW 90 Proceedings October 1990
inevitably leads to parallax problems. Investigating the effect of this and similar factors
in the regulation of conversation from the videotaped data of VideoWindow system use is
the subject of ongoing work in our laboratory.
Social Relationships:
Over the long term, a technology like the VideoWindow system, if it is successful,
should alter the perceived social relationships among those who are exposed to the
technology. This would parallel the proximity effects [Alle771 that point to increased
social closeness among those who work together in close physical proximity. However,
our data did not replicate this finding for the VideoWindow system. In all likelihood, the
existing pattern of social relationships among researchers was too engrained, and the
numbers of unplanned interactions too few, for the social patterns to be altered
sufficiently during the course of a 3 month trial.
CONCLUSIONS
The VideoWindow system experiment indicated that the technology can provide, to a
degree, an increased sense of a shared space between remote coworkers. There are certainly
instances in which, to an outside observer, a communication event appears to occur in a
quite natural manner. For example, a sneeze from a person who happens to be in the
VideoWindow system space at one end is answered, quite spontaneously, by a
“Gesundheit!” from someone who happens to be at the other end. However, for the
reasons noted above, this degree of informality is often not obtained. In fact, even when
all of the factors outlined are accounted for, we believe that the current VideoWindow
system lacks something due to factors we do not understand. One problem may be that
the apparent distance/size constancy mechanisms that the human perceptual system uses
to judge the distance and size of objects do not operate correctly over this technology. In
addition, it may be that even with life sized images, the psychological distance to
someone at the other end of a VideoWindow system link is greater than that in a
comparable face-to-face situation. People had to work very hard in the face-to-face
situation to ignore someone who was physically in the same room. When they wanted to
avoid conversation, people went to great lengths to avoid eye contact. In contrast,
ignoring another person on the opposite side of the VideoWindow system was much
easier, and looking at them didn’t seem to bring with it the obligation to engage in
conversation. In spite of its value, the VideoWiadow system currently does not provide
the same degree of social intimacy as does face-to-face interaction.
The implications of this experiment are clear. First, we must pay close attention to the
human factors of system design. Simply connecting two locations is not enough - we
must also ensure that the technology can be used easily and without errors. These
problems must be engineered out of the system to the degree that this is possible. This
is especially important with audio/video systems, because while these technologies appear
to be like face-to-face communication, the subtleties of camera framing and audio
placement lead to important differences that users can’t be expected to articulate. We must
learn more about how the characteristics of video/audio technology affects the usability of
telecommunications systems and attempt to resolve problems caused by technology that
is insensitive to user behavior. Second, we must reduce the behavioral cost to the user of
gaining access to the technology in the first place. One solution to this problem may be
to bring the system to the user. Finally, we must address the sampling problem: we
must get in touch with the right people regardless of their location.
ACKNOWLEDGMENT
We wish to thank L. Smoot and T. Judd, principal inventors of the VideoWindow system
technology, for their help and cooperation during this study.
CSCW 90 Proceedings October 1990
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089791402-3/90/0010/0011 $1.50
CSCW 90 Proceedings October 1990
11
