Steve Whittaker
stevew@research.att.com
David Frohlich
dmf@hplb.hpl.hp.com
Brid O'Conaill
boc@hplb.hpl.hp.com
(c) 1997, Lawrence Erlbaum
Note: This is a digitized copy derived from a copyrighted work published by Lawrence Erlbaum Associates. LEA did not prepare this copy and does not guarantee that it is an accurate copy of the author's original work.
As this book has shown, when video is used to support planned meetings, its benefits are relatively subtle and subjective. Video helps people manage the mechanics of conversation and understand nuances in meaning, and participants find meetings more satisfying if they can see one another (Isaacs & Tang, 1994; Dykstra-Erickson, Rudman, Hertz, Mithal, Schmidt & Marshall, 1995; Rudman, Hertz, Dykstra-Erickson & Marshall, this volume). But the presence of video does not have dramatic, immediately apparent effects on the work at hand, unless that work is inherently visual (Ochsman & Chapanis, 1974; Argyle, Lalljee & Cook, 1978; Short, Williams, & Christie, 1976). Although we certainly consider it important to enable richer interactions in pre-planned meetings, in this chapter we focus on the possibility of using video to support the more common, but less noticed, unplanned interactions, and in particular in the initiation of such conversations.
Our notion is that video may be a natural medium to support impromptu interactions because such interactions depend on each person knowing that the possibility of an interaction exists. Visual information is crucial for supporting the "sightings" that are a prelude to impromptu workplace conversations (Kendon & Ferber, 1973, Fish, Kraut, Root & Rice, 1993, Kraut et al., 1990a). We believe that, in addition to supplementing the verbal channel in interactions once they occur, video could also help make those impromptu interactions possible. Only a few systems have been designed to support the informal interactions that occur among co-located people in the workplace (Root, 1988; Tang & Rua, 1994; Bly, Harrison & Irwin, 1993; Gaver et al., 1992), and none are designed to enable purely chance encounters (although they sometimes happened in the existing systems). In this chapter, we will explore the type of applications that could be designed to support informal, and in particular, spontaneous communication.
A variety of research labs have built systems to enable quick connections between two or more people. Bellcore's Cruiser (Root, 1988), Toronto's CAVECAT (Mantei et al., 1991), SunSoft's Montage (Tang & Rua, 1994), DEC's Argo (Gajewska, Kistler, Manasse & Redell, 1994), and the Media Spaces at Xerox PARC (Bly et al., 1993) and EuroPARC (Gaver, et al., 1992) are examples of systems designed to be used from the computer desktop. However, like their commercial counterparts, all these applications except the Media Spaces and a feature of the Cruiser system (described below) are "connection-based" in the sense that a person explicitly decides to initiate an interaction. We will argue that these unplanned but intentional interactions are but one style of impromptu interaction; there are other more opportunistic types of informal interactions that have not been fully explored. We claim that these other classes of interactions are frequent and crucial for accomplishing work. Despite their importance, informal interactions are especially hard to support in distributed groups. We therefore characterise design requirement and discuss technologies to support informal communication across distance.
The above systems have three features that allow for the possibility of supporting opportunistic interactions. One is "virtual shared offices," where people keep a connection open between their offices indefinitely. Users of Xerox's Media Spaces were encouraged to do this, and users of Cruiser and Montage also created virtual shared offices on their own. In these cases, people can have extremely quick, spur-of-the-moment interactions because the link is "always open." However, interactions can occur only among those who are already connected. There are no facilities for overriding or interrupting existing links, and so others cannot join existing interactions unless they are physically near one of the people sharing a link.
Another example is the Autocruiser feature in Cruiser, which automatically made connections with a random series of people, each of which timed out if no one enabled the connection. This feature was intended to encourage opportunistic communication, but when tested, users found it "highly objectionable." The authors explained that "[u]nlike the random encounters that occur multiple time a day when two people are colocated, the Autocruises did not allow people to conduct the subtle nonverbal negotiations that regulate the entree into conversation." (Fish, et. al, 1993, pp. 52). This experience indicates that it is not enough to simply enable opportunistic communication; rather, the system must be designed to help people initiate these interactions naturally.
Finally, Portholes enabled awareness through a matrix of static images of other people's offices, and those images were updated every five minutes (Dourish & Bly, 1992). Upon seeing that someone was available, users within a site could create an audio-video connection. The Argo system also included a "hallway" of slowly updating video images (Gajewska, Manasse & Redell, 1995).
These findings give us a glimpse of the possible design requirements for a system that enables impromptu communication, but they are just the beginning. In this chapter, we will explore in more detail the requirements for a such a system. We will do this by describing the current data about informal interactions, presenting a new classification of the functions they fulfill, and then speculating about desirable properties of an application designed to support informal communication among distributed people. We hope this exploration will help illuminate the value of video in supporting informal communication and stimulate ideas about how to do so successfully.
(b) Intended: Interactions that occur when one person seeks out another to discuss a specific topic, but where there is no pre-arranged plan to talk.
(c) Opportunistic: Interactions that occur when one person happens to see another and remembers that they wanted to discuss a particular topic with them.
(d) Spontaneous: Interactions that occur because two people happen to see each other and get into a conversation on a topic not prepared by either person.
Extract 1.(2) A short opportunistic interaction (ROffice47, 0min:8sec)
The following interaction shows an unplanned conversation between Richard and Frank that occurred immediately after Frank had finished a phone call to a client. It arose because Richard heard Frank's phone call and opportunistically monitored the outcome. It continues with Richard offering unprompted advice and assistance.
Extract 2. An intended interaction leading to unprompted advice (ROffice 66, 28sec of 1min:36sec)
These conversations, which are representative of the HP corpus, along with data from various other sources, suggest a characterisation of work in which people are engaged in multiple intermittent and interleaved collaborative tasks. Workers frequently seek out and are sought out by their coworkers for brief interactions. These conversations often have a history of prior interactions and workers are often concurrently engaged in multiple interaction threads. More specifically, the available data show that, despite some variation due to job type, interpersonal communication has the following properties:
Data from the organisational communication literature adds evidence that interpersonal communication improves group performance and helps keep organisations healthy. Several such studies have looked at strong and weak ties within organisations, where strength is a function of frequency of contact, reciprocal favours or obligations, emotional intensity, and intimacy (Granovetter, 1973). A common finding is that although both high and low performing groups maintain both strong and weak ties, high performing groups tend to have a higher proportion of weak ties than do low performing groups (Nelson & Mathews, 1991). It is likely that the weak ties examined in these studies are based largely on informal communication, and in particular on opportunistic and spontaneous communication. Nelson & Mathews (1991) explain that weak ties to those outside a work group reduce a group's tendency to become insular and to negatively stereotype other groups. Weak ties also have been found to enhance "information flow and permeability of organisation boundaries," and to "foster flexibility and effective decision making" (Nelson & Mathews, 1991, pp. 371). Groups with many weak ties were also more accepting of innovations (Nelson, 1986).
Despite research from a various disciplines showing the value of informal interactions, evidence indicates that people in the workplace do not recognise its value. Kraut & Streeter (1995) found that impromptu communication is under-utilised compared with its value, whereas formal communication techniques are overused relative to their value. Our own preliminary evidence supports this result. In a series of interviews with a dozen employees in a Fortune 500 U.S. corporation, we found that although people reported gaining most of their work-related news and information from informal interactions, those same people said they used almost exclusively formal approaches to convey information to other parts of the company. Most commonly, they reported their information to a high-level management group and asked that they pass the information down the hierarchy in their staff meetings. In many cases, they wrote a document to convey information and either gave it to managers to give to their employees, or made it available to employees directly (in email, mailings to the home, or by publishing it on the company's internal World Wide Web pages). Some also gave formal presentations to supplement the document. When we asked information disseminators if they had considered spreading their information through word of mouth, they either had not thought of it or did not trust it. They were concerned that information passed informally would be distorted and misinterpreted and might not become available to all the intended recipients.
Based on a content analysis of 377 unscheduled face-to-face and telephone interactions in the HP corpus, we developed a simple classification of the functions of informal communication. We identified six functions: tracking people, taking or leaving messages, making meeting arrangements, delivering documents, giving or getting help, and reporting progress and news.
Extract 3. A tracking request made by Maureen to Bina about Ian (BOffice35, 9secs).
Extract 4. Bina requests that Sue take a detailed message for Catherine (BRoam12, 1min02sec).
Extract 5. A meeting invitation or offer made by Jane to Bina (BOffice31, 0min:16sec)
Extract 6. Rose hands over a letter to Richard for signing (ROffice50, 0min:8sec)
Extract 7. Rose requests help from Richard (RRoam21, 28sec).
Extract 8. Bina offers a news report on Adjay to Nigel (BRoam42, 26sec of 1min:42sec)
Direct requests for updates were also common, as in Richard's "Is he alright?" to Frank after Frank's phone call in Extract 2. Note that these exchanges are not always between teammates working on the same projects. Reporting progress and news is a flexible way of maintaining and consolidating contact with ex-teammates and others with whom there has been contact in the past.
We can now see how informal interactions contribute to McGrath's (1991) three functions of groupwork. Many help, news, and document-related interactions contribute to the production function of a group by solving individual or shared problems as they arise, providing relevant pieces of information at just the right time, and by controlling the quality of transactions and outputs. In addition, tracking, message, and meeting arrangement interactions are indirectly supportive in that they provide ways of sustaining and planning the other kind of contacts with absent or busy partners.
These last three kinds of interactions, however, are more central to the social functions of the group, i.e. group maintenance and member support. They help group maintenance by providing ways for members to learn about each other's activities, and therefore to adapt their contributions to the group's output. Document, help, and news related interactions also help maintain the group by monitoring and controlling individuals' work in ways that bring it into line with group objectives. They also help keep people mutually accountable for their commitments. We can easily imagine that the combined effect of these interactions is to make people feel `part' of the group.
Finally, through message, help, and news related interactions individuals receive several forms of `member support.' Message-taking constitutes practice in covering for others and hence trains people in new roles and responsibilities. Getting help provides emotional as well as task support. Reactions to progress reports are natural occasions on which to praise people for achievement, while news updates help maintain long-term relationships with people who may become closer colleagues in future group work.
We often think of workgroups in terms of our immediate colleagues. These are the people with whom we perform our primary work function. However, people also have many interactions with colleagues throughout and outside an organisation. We suggest that there are three types of workgroups in addition to project groups: cross-functional, peer, and external.
Cross-functional groups are those that cross organisational boundaries, often to perform a short-term activity. For example, a short-term workgroup crossing the finance and production departments may form to clear an expense claim or place a purchase order. Peer workgroups are networks between people of the same profession or past colleagues. These groups provide professional guidance and support that may not be available within the project group. Finally we use the term external to describe the many relationships that exist with partners outside the organisation. Clients, suppliers and contract staff would fall into this category.
TABLE 1. Characteristic differences by group type
All four group types have different needs and constraints that affect their patterns of communication. Based on a preliminary analysis of the HP corpus using these definitions, we consider how communication in these workgroups might differ. These are summarised in the Table 1.
The long-term duration of such relationships and their recognition by organisations again make them likely candidates for technology support. However, the communication requirements may be sporadic so the technology may appear at times to be under-utilised, which may make expensive systems difficult to justify. Cross-functional group members are likely to be spread out, perhaps within a building or even across sites. The ability to track members or leave detailed messages during active periods would be useful. Although the control of equipment is within a single organisation there may be departmental differences. Standardisation of technology would be desirable.
Given the importance and frequency of informal communication, how can we support it in these newly distributed groups? In particular, what role will video play in that efort? Providing technological support for informal interactions is a challenge because, unlike meetings, which happen at predetermined times among predictable groups of people in predefined locations, informal interactions have few defined variables. They occur with little notice for short periods of time, often between participants whose identities cannot be predicted in advance. The topics are unplanned, but they often build on previous conversations, so any document or supporting material may become relevant. We attempt to take on the challenge of providing support for informal interactions by dividing the problem into two issues. We first consider how we might help people enter informal interactions and then discuss features that might help support those interactions once they begin.
Why is this? One problem with intended interactions is that the availability of the recipient is not guaranteed. One method of helping people find good times to interact is to use techniques such as "glancing" (Root, 1988; Tang & Rua, 1994) to offer people information about the availability of the recipient. By "looking into" the recipient's office they can see whether the person is present and available for conversation. Once availability has been established, it is critical to establish connections (such as audio, video, and data sharing) extremely quickly and easily. Studies of existing prototypes show that if a connection is not made within a few seconds, people tend to use the system for longer, more formal interactions (Tang & Isaacs, 1993; Fish et al., 1992).
On occasions when recipients are unavailable, it is useful to provide mechanisms to set up future contact, most notably the ability to leave a note in a prominent place. Montage, for example, allows people to leave an electronic "Stickup" note on the screen of someone they tried to contact. The recipient can use that note when they return to establish a video connection with the sender. This feature was well received by users (Tang, et al., 1994).
In addition, we have shown that people often go to another colleague if they do not find the person they seek. Perhaps a system for intended interactions could allow people to designate a "next relevant colleague" to whom people could "go" when appropriate. Another possibility is to provide a "contact method" for the recipient. A more sophisticated but complex design would allow the user to specify different people for different topics. In addition, we noted that people often announce to their colleagues upcoming events that will take them away from their work area, thus encouraging others to handle pending business with them. A distributed system might support a similar activity, perhaps by enabling a group video connection or a prominent place to leave a note to a group.
In the Montage system, people can post an image for those who glance to indicate they are not in the office (Tang & Rua, 1994). They can also write a message on the image to give more information. Data from an extended use study showed that 87% of the times users put up the "not available" sign, they wrote a note indicating their whereabouts and/or when they would return. They never specified another person to contact, however. This finding indicates that a forwarding feature might need to be built in to facilitate the behavior.
Finally, it might be useful to provide a message capability that goes beyond text or voice alone. Users may want to make better use of missed connection events by leaving richer multimedia messages incorporating a combination of voice, gestures, writing, and documents.Wang's Freestyle system allowed users to do this by freezing the image of a document on the screen, which users then annotated and spoke about in a recorded "voice over" message (Francik, Rudman, Cooper, & Levine, 1991). Frohlich and Daly-Jones (1995) tested a similar pen-and-voice messaging facility called Voicefax against standard PC fax and voice mail messages. They found that people used significantly fewer Voicefax messages to perform the same task with higher perceived quality. It is not hard to imagine a video-based variation on these systems that allowed users to switch on a local document camera to record a video message for dispatch with its associated documentation.
In sum, features that would be useful to set up contact include:
In a distributed environment, people can use video to stay aware of others' availability. In the PARC Media Space, for example, a camera was placed in a commons area largely to help people stay aware of others' whereabouts (Bly, et. al., 1993). People can use such video to see when people come into camera range. They can see such things as body position, facial expression, eye contact, and other cues about a person's focus of attention. They can tell whether a person is already involved in an interaction, and if so, whether it might be appropriate to join. In other words, video allows people to use many of the same cues they use in a shared physical environment to understand who is where and whether they are willing to interact. We described many examples from the HP corpus when people used visual cues to time their opening comments. There were other cases when people used visual cues to indicate they would prefer not to initiate conversation. People also used visual cues on occasion to show that they were ready to end interactions.
Still, simply providing video access among remote collaborators is not sufficient for enabling smooth entry into interactions. People also need to know when they are likely to encounter others so that they can adjust their demeanour appropriately. The Autocruiser feature of Cruiser was not well received in part because people were given no warning of pending video connections and because they had no relevant shared context when a connection was made (Fish, et. al, 1992). The Montage system used approach sounds to signal a pending interaction and a slow video fade-in effect to soften the intrusiveness of the video connection (Tang & Rua, 1994). Perhaps such sounds and video effects could be used to signal the proximity of others. In addition, certain "places" in a shared electronic work environment could be created where people could "run into" others. These places might provide other attractions that draw people (e.g. daily news, schedule of events, progress schedule) so that unintended interactions might occur.
In our experience, users of video systems often ask for the ability to control visual access. One way to do so is to design all connections to be symmetric so that no one can watch or listen without being seen and heard themselves. In addition, explicit access controls can be provided.
These ideas suggest the following components for a system to support unintended interactions:
A related concept is to enable people to store different aspects of their conversations, including documents, audio, video, and screen snapshots. By storing these conversation components, people could keep track of progress, keep others informed, and perhaps resolve later misunderstandings. One such system is Filochat, a conversational support tool that co-indexed user's pen strokes during note-taking to an audio recording of the meetings. Field study results showed that this system helped people regenerate the context of prior meetings from handwritten notes (Whittaker, Hyland & Wiley, 1994b). A system developed at Xerox PARC called WhereWereWe enables real-time video capture, indexing, and playback during conversations, which was used successfully to support and track design and planning sessions (Minneman, et al., 1995).
Storing conversations might also help those who wish to convey a message to a large group but do not trust word of mouth. For example, creators of information could make their message easily available on line (in text, audio, video, or otherwise), so that anyone passing on that information could easily share the first-hand version. The information might include a link to the information creator so that people could easily contact them (though video or otherwise) if they had questions. Perhaps mechanisms could be included to track those who had seen the message so that the information creator could contact groups who had not received the message.
Ideas discussed to support interactions that happen spontaneously include:
In general, it may make sense to build in a notion of groups, which people may define and control as an entity rather than specifying access on a per-person basis. Of course, group membership is often fluid, especially for ad hoc teams. A community of peers may not even see themselves as a "group." There may be a need for official groups, where all the members acknowledge the boundaries of the group, as well as unofficial groups, which a person creates a group to characterise the level of access they will allow a set of people.
To support external groups, tools must interoperate across computer platforms. Even within the same company, different groups often work on different hardware using different software. A system designed to support their ability to notice each other and enter into unplanned conversations should run smoothly across a variety of platforms.
Possible ways discussed to handle different types of groups include:
Argyle, M., Lalljee, M., & Cook, M. (1968). The effects of visibility on interaction in a dyad. Human Relations, 21, 3-17.
Bly, S., Harrison, S., & Irwin, S. (1993). Media Spaces: Bringing people together in a video, audio and computing environment. Communications of the ACM, 36:1, 28-45.
Boden, D. (1994). The Business of Talk: Organisations in Action. Cambridge: Polity Press.
Dourish, P. & Bly, S. (1992). Portholes: Supporting awareness in a distributed work group, Proceedings of the Conference on Computer Human Interaction, (541-547). Monterey: ACM Press.
Dykstra-Erickson, E., Rudman, C., Hertz, R., Mithal, K., Schmidt, J., & Marshall, C. (1995). Supporting adaptation to multimedia desktop conferencing. Proceedings of the 15th International Symposium on Human Factors in Telecommunications, Melbourne, Australia.
Festinger, L., Schachter, S. & Bach, K. (1950). Social pressures in informal groups: A study of human factors in housing, New York: Harper & Row.
Fish, R., Kraut, R., Root, R. & Rice, R. (1992). Video as a technology for informal communication. Communications of the ACM, 36:1, 48-61.
Francik, E., Rudman, S.E., Cooper, D. & Levine, S. (1991). Putting innovation to work: Adoption strategies for multimedia communication systems, Communications of the ACM, 34:12, 53-63.
Finholt, T., Sproull, L., & Kiesler, S. (1990). Communication and performance in ad-hoc task groups. In J. Galegher, R. Kraut & C. Egido, (Eds.), Intellectual Teamwork. (291-325). Hillsdale, N.J.: Lawrence Erlbaum Press.
Frohlich D. (1995). Requirements for Interpersonal Information Management. In Thomas, P.J. (Ed.) Personal information systems: Business applications, Cheltenham: Stanley Thornes in association with Unicom Seminars, 133-153.
Frohlich D. & Daly-Jones O. (1995). Voicefax: A shared workspace for voicemail partners. In Companion Proceedings of Conference on Computer Human Interaction. (308-309). Denver: ACM Press.
Gajewska, H., Manasse, M.S., & Redell, D.D (1995). Argohalls: Adding support for group awareness to the Argo telecollaboration system, Proceedings of User Interface Software and Technology, (157-158). Pittsburgh: ACM Press.
Gajewska, H., Kistler, J. Manasse, M.S., & Redell, D.D. (1994). Argo: A system for distributed collaboration, Proceedings of Multimedia, (433-440). San Francisco: ACM Press.
Gaver, W., Moran, T., MacLean, A., Lovstrand, L., Dourish, P., Carter, K., & Buxton, W. (1992). Realizing a video environment: EuroParc's RAVE system. Proceedings of Conference on Computer Human Interaction, (27-35). Monterey: ACM Press.
Granovetter, M. (1973). The strength of weak ties, American Journal of Sociology, 78, 1360-1380.
Harper, R., & Sellen, A. (1995). Collaborative tools and the practicalities of professional work at the International Monetary Fund, Proceedings of the Conference on Computer Human Interaction, (122-129). Denver: ACM Press.
Isaacs, E.A., & Tang, J.C. (1994). What video can and cannot do for collaboration: A case study, Multimedia Systems, 2, 63-73.
Kendon, A., & Ferber, A. (1973). A description of some human greetings, In R. Michael & J. Crook, (Eds.), Comparative Ecology and Behavior of Primates, London: Academic Press.
Kraut, R., Fish, R., Root, B., & Chalfonte, B. (1990a). Informal communication in organizations: Form, function and technology. In S. Oskamp & S. Spacapan, (Eds.), People's reactions to technology in factories, offices and aerospace, The Claremont Symposium on Applied Social Psychology, Sage Publications, 145-199.
Kraut R.E., Egido C., & Galegher J. (1990b). Patterns of contact and communication in scientific research collaboration. In J. Galegher & R. Kraut (Eds.), Intellectual teamwork: The Social and technological bases of cooperative work. Hillsdale, NJ: Erlbaum.
Kraut, R.E. (1987). Predicting the use of technology: The case of telework, in R.E. Kraut (Ed.), Technology and the transformation of white collar work, Hillsdale, NJ: Erlbaum.
Kraut, R.E., & Streeter, L.A. (1995). Coordination in software development, Communications of the ACM, 38:3, 69-81.
Luff, P., Heath, C., & Greatbatch, D. (1992). Tasks-in-interaction. Paper and screen based documentation in collaborative activity. Proceedings of Conference on Computer Supported Co-operative Work, Toronto: ACM Press, 163-170.
MacLeod, L., Scriven, J., & Wayne, F.S. (1992). Gender and management level differences in the oral communication patterns of bank managers, Journal of Business Communication, 29:4, 343-365.
Mantei, M.M., Baecker, R.M., Sellen, A.J., Buxton, W.A.S., & Mulligan, T. (1991). Experiences in the use of a Media Space, Proceedings of the Conference on Computer-Human Interaction, (203-208). New Orleans: ACM Press.
McGrath (1991). Time matters in groups. In J. Galegher & R. Kraut (Eds.), Intellectual teamwork: The social and technological bases of cooperative work, Hillsdale, NJ: Erlbaum, 23-61.
Minneman, S.L., Harrison, S., Janssen, B., Kurtenback, G., Moran, T., Smith, I., & van Melle, B. (1995). A confederation of tools for capturing and accessing collaborative activity, Proceedings of the Conference on Multimedia, San Francisco: ACM Press, in press.
Mosier, J., & Tammaro, S. (1995). Video teleconference use among geographically dispersed work groups: A field investigation of usage patterns and user preferences, Journal of Organizational Computing, 4, 343-366.
Nelson, R,. & Mathews, K.M. (1991). Network characteristics of high-performing organizations, Journal of Business Communications, 28:4, 367-386.
Nelson, R. (1989). The strength of strong ties: Social networks and intergroup conflict in organizations, Academy of Management Journal, 32:2, 377-401.
Ochsman, R.B., & Chapanis, A. (1974). The effects of 10 communication modes on the behavior of teams during co-operative problem-solving, International Journal of Man[sic]-Machine Studies, 6, 579-619.
O'Conaill B., & Frohlich, D. (1995). Timespace in the workplace: Dealing with interruptions. Companion Proceedings of Human Factors in Computing Systems, (262-263). Denver: ACM Press.
Olson, M. (1987). Telework: Practical experience and future prospects, In R.E. Kraut (Ed.), Technology and the transformation of white collar work, Hillsdale, NJ: Erlbaum.
Panko, R. (1992). Managerial communication patterns, Journal of Organisational Computing, 2, 95-122.
Pickering, J.M, & King, J.L. (1992). Hardwiring weak ties: Individual and institutional issues in computer mediated communication. Proceedings of the Conference on Computer-Supported Cooperative Work, (356-261). Toronto: ACM Press.
Reder, S. & Schwab, R.G. (1990). The Temporal Structure of Cooperative Activity, Proceedings of the Conference on Computer-Supported Cooperative Work, (303-316). Los Angeles: ACM Press.
Root, R. W. (1988). Design of a multi-media vehicle for social browsing, Proceedings of the Conference on Computer-Supported Cooperative Work, (25-38). Portland: ACM Press.
Rudman, C., Hertz, R.L., Dykstra-Erickson, E., & Marshall, C., Information density as a driver for adoption of video for distributed group work, this volume.
Sellen, A., & Harper, R., Video in Support of Organisational Talk, this volume.
Short, J., Williams, E., & Christie, B. (1976). The social psychology of telecommunications, London: Wiley & Sons.
Sproull, L. (1984). The nature of managerial attention, In L. Sproull and J. Larkey (Eds.), Advances in Information Processing in Organizations, JAI Press.
Suchman L., & Wynn E. (1984). Procedures and problems in the office. Office: Technology and People, 2, 133-154.
Tang, J. (1991). Findings from observational studies of collaborative work. International Journal of Man{sic]-Machine Studies, 34, 143-160.
Tang, J.C., Isaacs, E.A., & Rua, M. (1994). Supporting distributed groups with a Montage of lightweight interactions, Proceedings of the Conference on Computer-Supported Cooperative Work, (23-34). Chapel Hill, NC: ACM Press.
Tang, J.C., & Isaacs, E.A. (1993). Why do users like video? Studies of multimedia-supported collaboration, Computer Supported Cooperative Work: An International Journal, 1:9, 163-196.
Tang, J.C. & Rua, M. (1994). Montage: Providing teleproximity for distributed groups, Proceedings of the Conference on Computer Human Interaction, (37-43). Boston: ACM Press.
Whittaker, S., Frohlich, D., & Daly-Jones, O. (1994a). Informal workplace communication: What is it like and how might we support it?, Proceedings of the Conference on Computer Human Interaction, (131-137). Boston: ACM Press.
Whittaker, S., Hyland, P., & Wiley, M. (1994b). Filochat: Handwritten notes provide access to recorded conversation, Proceedings of the Conference on Computer Human Interaction, (271-277). Boston: ACM Press.
Whittaker, S., Swanson, J., Kucan, J., & Sidner, C. (unpublished manuscript). Managing lightweight interpersonal communications. Paper submitted.
(2) The following conventions are used in the transcriptions: