C H I 9 9 1 5 - 2 0 M A Y 1 9 9 9

Chat CirclesPapers

Fernanda B. Viegas and Judith S. DonathMIT Media Lab20 Ames Street

Cambridge, MA 02139 USA+1 617 253 9690

{fviegas|judith}@media.mit.edu

ABSTRACTAlthough current online chat environments provide newopportunities for communication, they are quite constrainedin their ability to convey many important pieces of socialinformation, ranging from the number of participants in aconversation to the subtle nuances of expression that enrichface to face speech. In this paper we present Chat Circles,an abstract graphical interface for synchronous conversa-tion. Here, presence and activity are made manifest bychanges in color and form, proximity-based filtering intu-itively breaks large groups into conversational clusters, andthe archives of a conversation are made visible through anintegrated history interface. Our goal in this work is to cre-ate a richer environment for online discussions.

Keywordschatroom, conversation, social visualization, turn-taking,graphical history, Internet, World Wide Web

INTRODUCTIONThe history of networked computing shows that, given achance, people will adapt technology for social interaction.E.g., although the ARPANET was developed for remoteoperation of computers, email and newsgroups havebecome among its most popular (and arguably, most impor-tant) uses [5]. More recently, online service providers havediscovered that chat, email and other communicative activi-ties are the key services that people want.

Yet, although interpersonal communication has proved to bean extraordinarily popular and influential use of the com-puter, the conversational interfaces in use today are stillquite primitive, making it difficult to convey many basicsocial cues. With that in mind, we have developed Chat Cir-cles, a chat system that uses abstract graphics to create aricher, more nuanced communicative environment.

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CURRENT INTERFACESThere are currently a wide variety of tools that allow forsynchronous communication over a computer network.Internet Relay Chat (IRC), for instance, is one of the Inter-net’s most popular applications for interpersonal communi-cation. And, although the World Wide Web’s initialprotocols were not conducive to live interaction, the adventof Java has made Web-based chatrooms increasingly popu-lar.

When email, newsgroups and chatrooms were first devel-oped, ASCII interfaces were the norm: most systems lackedboth the power and the infrastructure for more elaborategraphical interfaces. Today, although faster computers andnetworks as well as support for visual routines make graphi-cal interfaces quite feasible, text still dominates the arena ofon-line conversations [fig 1 b]. The reasons for this may bepartly tradition - a combination of familiarity and an estab-lished application infrastructure - and partly a lack of alter-natives - many of the existing graphical systems havesignificant drawbacks.

In a text-only communication environment, the text elementis overloaded as a multiple signifier. In these environments,the participants type messages which are then displayedsequentially on each person’s screen. These messages con-vey two types of information: one is the content of the mes-sage, the other is the presence of the participant.Consequently, if the participant is not actively messaging,he or she is not present on the screen. This ephemeral pres-ence has a strong impact on the style of discourse, for par-ticipants often feel compelled to constantly post messagesso that they will not be forgotten by the others.

Much important contextual information is difficult to per-ceive in a text-only chat system. The number of participantsis hard to gauge: a session containing 20 users looks nearlythe same as a session with two users. It is difficult to distin-guish among the participants and form a coherent sense oftheir individual identities: the users all resemble each othervisually, appearing as a user name in text against the back-ground. The interactions among the users are not manifest,for the conversation always appears on the screen as a linearprogression of lines of text, regardless of the conversation’sdynamics. Finally, the temporal information found in oralconversation, such as turn-taking and the negotiation ofconversational synchrony by the participants, is not cap-tured by these sequential lines of text.

There are alternatives to text-based chats. In recent years anumber of graphical chat interfaces have been developed;among the most popular systems are: The Palace [12],Comic Chat [4], and V-Chat [13]. These graphical environ-ments make use of avatars to convey social presence andidentity. Avatars can be pictures, drawings or icons thatusers choose to represent themselves. In the case of ThePalace, for instance, these figures range from simple smileyfaces to highly elaborate (often Medieval or sci-fi themed)animated drawings. Graphical chatrooms also make use ofbackground graphics that are designed to transform eachroom within the system into a unique experience [fig la].On all graphical chat systems, however, text is still used forthe actual conversation; users communicate with others viatyped text that appears in “speech balloons” that pop up nextto the participants’ avatars.

The problem of overly ephemeral presence is solved in thegraphical chats: one’s avatar is continuously displayed on

an effective solution for making presence in these environ-ments more substantial and permanent, making it much eas-ier for users to see how many people are participating in aconversation at any given time, even if users are not activelymessaging. Moreover, it becomes much easier for users tofollow who is saying what during a conversation becausethey do not have the overhead of having to read the speak-ers’ names every time something is posted on the screen;one needs only see which avatar “spoke” last.

1. One exception is Comic Chat, where the systemonly displays “active” avatars on each one ofthe comic frames.

Although the use of avatars solves the problem of presence,it introduces new difficulties. Space needs to be allocatedfor every user’s avatar as well as for their speech bubbles.The screen becomes quickly cluttered, which can hindercommunication. More subtly, the avatars can distort expres-sion and intent by providing a small range of (often broadlydrawn) expressions that overlays all of a user’s communica-tions. Even if an avatar has several expressions, and manydo, it is still a far cry from the subtlety of verbal expression,let alone our physical gestures.

The user interface in avatar systems, like text-based chat-rooms, is not very supportive of the implicit interactivepractices present in face to face conversation. There is noexpressive way of conveying turn-taking rhythms nor pat-terns of replies to specific utterances. Social presence,although permanent, is still given a binary quality in graphi-

tler reading of presence is allowed.

CHAT CIRCLESChat Circles is a graphical interface for synchronous com-munication that uses abstract shapes to convey identity andactivity. Our aim is to use graphics to convey the dynamicsof conversation as well as to unveil the patterns of activitythat emerge through the interaction among users. Weemploy simple 2D graphics that change in shape, size andcolor to communicate the rhythm of conversations.

The interface in Chat Circles also features a proximity-based filter that allows users to focus on the conversation inwhich they are involved without, however, losing track ofthe activity level in the rest of the system.

Each participant is represented by a colored circle on thescreen in which his or her words appear. The circles grow

Paners

and brighten with each message, and they fade and diminishin periods of silence, though they do not disappear com-pletely so long as the participant is connected to the chat.

IdentityEach person who is connected to the chat’s server appears asa colored circle [fig 2]. Users choose a color upon loggingin and color thus serves as a general indicator of identity.Participants are also identified by name, a small label nextto each participant’s circle displays their name in the samecolor as their corresponding circle. The local user’s specificcircle is differentiated from the other circles through a whiteoutline; this makes it easy for users to locate themselves onthe screen at any point in time.

Most people can discriminate among a limited number ofnon-adjacent colors; once the number of participants risesabove that number, color identification will become some-what ambiguous. However, we believe it will still be usefulfor two reasons. First, we are much better able to discrimi-nate between adjacent colors. Chat Circles is designed sothat participants in a particular discussion must be near eachother on the screen, so within the group with which one isengaged, the ability to distinguish between say, two shadesof blue, will be higher than for the screen as a whole. Sec-ond, many participants are likely to remain in the same spotfor extended periods of time, and thus location will supple-ment color as an identifying cue.

Color in Chat Circles does not carry any intrinsic meaning.For instance, red does not necessarily mean anger, nor yel-low suggest happiness. Indeed, it is one of the challenges inthis project to find a palette of colors that will not inadvert-ently suggest meaningful interpretation: a bright yellow cir-cle might appear to be cheerful, and a dull brown onedepressed, regardless of the actual mood of the participantor the content of the speech.

ActivityIn Chat Circles, activity is conveyed through the changes insize and color of the graphics displayed on the user’s screen.The resulting graphical cadence becomes an important artic-ulator of the flow of conversations in the system.

When a user posts a message, his or her circle grows andaccommodates the text inside it. Postings are displayed for afew seconds (the exact time varies depending on the lengthof each posting) after which they gradually fade into thebackground. In moments of silence, users’ circles shrinkback to their original size as a colored dot on the screen.This approach mimics real life conversations where, at anygiven time, the focus is on the words said by the person whospoke last and, progressively, those words dissipate in themidst of the evolving conversation.

Color also plays a key role in communicating one’s overalllevel of activity. Participants’ circles appear bright whenthey post messages and the color progressively fades out inmoments of silence. Active users appear as bright circles onthe screen and those who have been idle appear as fadeddots. As mentioned earlier, one of the benefits of graphicalchats is that participants can see the full extent of the audi-ence, unlike in text-based ones, where the listeners areinvisible. Yet the appearance of a crowded, avatar-filledroom can be misleading if most of those depicted are notcontributing (and may, in reality, be far from their comput-ers). By fading the circles of non-active participants, ChatCircles can indicate both the overall number of connectedusers and the actual level of presence and activity. Hence,the rendering of social presence gets tied to the level ofactivity of each participant.

This approach aims at revealing the level of activity, or lackthereof, of each participant. It differs from text-based envi-ronments in that presence is continuous. In the tradition ofavatar interfaces, presence in Chat Circles is constant butthe level of participation is also made clear through the

presence is static. “Lurkers” - users that “listen” to conver-sations instead of actively contributing - for example,appear as faded dots on the screen.

The use of these dynamic graphics creates a sequence ofbright splashes of colors and fading circles in a pulsatingrhythm that reflects the turn-taking of regular conversations.

Conversational GroupingsWhat attracts people most, in sum, is other people.Many urban spaces are being designed as thoughthe opposite were true...

- William H. Whyte

Chats often have numerous rooms where users can engagein conversation with different people. One of the results ofsuch arrangement is that groups of people end up secludedfrom each other; one can’t be in more than one chat room ata time unless one logs in to the system multiple times andcreates various personas. We believe that opening up thevarious isolated rooms adds to the users’ social experienceof the chatroom at the same time that it allows for an overallview of the activity in the system at all times. For that rea-son, there are no “rooms within rooms” in our system. Oncea user logs in to Chat Circles, he or she sees all the otherparticipants in the entire system. Nevertheless, the userneeds to be physically close to other participants to be ableto “listen” to (i.e. to read) their conversation. Each person inthe system has a “hearing range” that allows him or her toengage in conversation only with people who are suffi-ciently close by. The other users, the ones outside the per-son’s hearing range, maintain their locations and colors butare rendered differently - their circles appear as outlined cir-cles instead of being fully colored and their messages arenot displayed [fig 3].

The physical proximity metaphor makes use of the abilitywe all have of peripherally and selectively sensing activityaround us. Whenever one attends a social gathering, such asa party for example, he or she immediately perceives theamount of people present and the level of activity in theenvironment. Even though the person might not be able tolisten to every single conversation in the room, activity as awhole is accessed at all times. The same is true in Chat Cir-cles for users are always aware of the number of peoplelogged onto the system as well as the activity level withineach cluster of conversation. Users see the physical move-ment and the fading patterns of other participants in the sys-tem therefore getting a greater awareness of the ebb andflow of discussions. The system makes it very easy to spotheated discussions - even when a user is not participating inone - because of the burst of “bubbles” on the screen asopposed to less active conversations where not much visualactivity takes place.

In chat systems there are usually numerous conversationsoccurring at the same time on the screen, a phenomenon thatmakes following discussion an exercise in winnowingthrough non-sequiturs. Simply having a graphical interface

does not solve the problem - people can still respond tostatements scattered across the screen without performingany action indicating which remarks they are addressing.We believe that the physical proximity metaphor we areimplementing will encourage conversational threads tobecome spatially localized. This changes the way in whichthe spatial dimension of the screen has been treated in chatsystems so far. By adding a new layer of meaning to thelocation of users on the screen, we cause their position tofilter out information from the outside at the same time thatit amplifies the contents of the “readable” material.

By tearing down the virtual walls of current chat systemsand by making spatial location meaningful, Chat Circlesreveals activity clusters and conversation patterns in users’interactions. Users are able to have two different and simul-taneous readings of the system: their immediate surround-ings - the conversation they are currently involved in - andthe overall reading of the state of the entire system. We hopethat this kind of multilevel interpretation of the chat spaceallowed in the Chat Circles interface will help provide amore contextualized experience of social presence online.

History

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Chatroom conversations tend to be thought of as remarkablyephemeral. Part of this sense of impermanence has to dowith the synchronous nature of the interaction itself. In thatrespect, communication in chatrooms is fundamentally dif-ferent from the kind of communication that happens, say, innewsgroup discussions. The latter consists mostly of wellthough out, complete statements written by users prior totheir posting. In chatrooms, however, the interaction is notthought out in advance and spontaneity permeates the con-versation. Just like in face-to-face conversation, there is noarchiving practice in effect; chats happen and then dissipate.

This need not be so. Like other kinds of computer-mediatedcommunication, online chats are intrinsically recordable.The way we choose to record and present the interactionthat takes place in chatrooms makes all the difference interms of readability and social impact. Chat logs read muchlike unedited transcripts of speech; they do not aid users inunderstanding the underlying patterns of activity and com-munication within specific conversations. Once again, allwe are given are the black letters on a white background, anarrangement that does not convey any of the most elemen-tary patterns of the social interaction they ought to represent[fig 5].Following one of the maxims of design, we believe that heretoo form should follow function. That is why we propose avisualization of the chat archive. Pursuing the sameapproach we took for the conversational interface, history inChat Circles also springs out of a concern for using graphicsto convey identity as well as to reveal social patterns ofinteraction. The abstract graphics of Chat Circles lendthemselves to creating a visual archive that is self-docu-menting in its highlighting of salient events. With that inmind, we have developed Conversation Landscape, an inter-face to visualize the conversational archive of online chats.

Conversation Landscape can be thought of as a two-dimen-sional (2D) model of the conversation, with the y axis repre-senting time. Just like in the conversational interface, eachuser here is represented by a different color (users keep thesame colors they had during the conversation for graphicalconsistency). The temporal sequence results in coloredthreads on the screen that, when viewed together, reveal theinteraction patterns within a conversation. Each participant’sthread displays individual postings as horizontal bars cross-ing the vertical time line [fig 4].

Because we make use of the time axis to display postings,we are able to create a much more faithful rendition of theinteraction between users than would be possible through aregular log file. In this archival interface, any horizontalslice of the Conversation Landscape represents a particularmoment in the conversation.

Single postings can be accessed on the history threadsthrough a mouse-over effect. When the mouse rolls overone of the horizontal bars, the latter becomes highlightedand the corresponding text appears to the right of that partic-ular bar [fig 6]. This provides a fast and intuitive way ofbrowsing through the specific contents of each posting ofthe archived conversation.

One of the most innovative aspects of the ConversationLandscape is that, when taken as a whole, the threadsinstantly reveal the interaction patterns of the conversation.Clusters of activity become self-evident as do periods ofsilence or pause [fig 7]. With every user’s archive displayed

P a p e r s . CHI 99 15-20 MAY 1999

on the screen, it is also very easy to spot inactive users aswell as people who tend to dominate conversations.Because threads are spatially displayed according to time,logins and logouts are readily perceived as such. Conse-quently, the interface allows for a visualization of bothgroup and individual patterns at the same time as it creates,by its mere shape and colors, a snapshot of an entire conver-sation in one image [fig 9].

Another issue brought forth by the archival interface is thatof privacy. Because Chat Circles records all the conversa-tions on the screen, it also makes data available about eachuser’s interaction during a chat session. Information such aswho the user was interacting with at any given point in aconversation is made public but this might not be desirableat all times.

The visualization of history in Conversation Landscape alsotakes into account user movement on the screen as well asthe “selective” patterns created by the hearing range featureof the conversational interface. Even though all users’threads are continuously displayed on the screen, one’s indi-vidual interaction history is made clear by the way in whichpostings get rendered. If a posting occurs within the user’shearing range it appears as a solid horizontal bar, however ifa posting occurs outside the user’s hearing range, it gets dis-played as an outlined horizontal bar. This graphical conven-tion follows the same design principle found in the chattinginterface of Chat Circles [fig 8].

Because of the ability to move, participants can easily get inor out of each other’s hearing range creating interesting pat-terns of interaction; this can be especially hard to visualizebecause it calls for the tracking of individual historieswithin a very fluid system. Our approach to showing theseindividual interactions follows the same concept found inthe conversational interface of nesting the individual datawithin group data. The ‘solid’ portions on other users’threads correspond to the time during which these users

were within the hearing range of the particular personwhose history we are looking at - the remaining portions ofthe other users’ threads fade into the background. This waywe can very quickly understand who was talking to whom atany point of the conversation. These readings of the archivethat are based on a single user’s point of view present uswith unique imprints of both the movement and the hearingrange aspects of the system. This is a way to make individ-ual information salient while still in the context off the entiresystem.

AestheticsA simple arrow concentrates more efficiently onpointing than does a realistically drawn Victorianhand with fingernails, sleeve, cuff, and buttons. Thearrow is also more nearly a full-time symbol andtherefore invites the beholder to treat it as a state-ment rather than a piece of the practical world

Char Circles relies on basic, abstract shapes to conveysocial presence and activity. We are working with circlesand other simple geometric elements for several reasons.Our interest in abstract visual representations of conversa-tion has to do with both what they do and do not (convey. Byrendering the conversation as a visual entity, we hope togive people a better sense of many of the social patterns thatare difficult to perceive in a computer-mediated discussion.Our goal is to clarify and highlight what is already there; wewish to avoid introducing spurious and potentially mislead-ing information, as it is all too easy to do with figurativerepresentations. The interface is minimalist in the sense thatevery aspect of graphical use relates to a function within thesystem; there is no decorative use of graphics.

Furthermore, the graphical appearance of the interfacebecomes highly meaningful in the way it affects the toneand feel of social interactions. Users tend to classify differ-ent virtual spaces somewhat in the same manner they clas-sify physical ones: depending on the attributes and feel ofthe environment, different sets of behavior are deployed.

In developing Char Circles we felt the need to break awayfrom the relative rigidity of textual environments for con-versations and, in doing so, we were faced with the questionof how to create an aesthetically inviting space for users tointeract. The use of abstract graphics allowed us to articu-late the interface metaphors of hearing range and historywithout the intrusion of the problem of likeness of represen-tation. Finally, the dynamic quality of the graphics added amore rhythmic and organic feel to the interface.

Current status: implementation and user feedbackChat Circles is implemented in Java and runs over theWorld Wide Web on browsers that support Java 1.1. Thechoice of developing this system as a Java applet complieswith our original goal of making the software highly acces-sible to users. Participants can choose to view their conver-sation either through the ‘chat’ mode, where each person is

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represented by a circle, or through the ‘history’ mode. Per-formance in Chat Circles is still not as fast as we would likeit to be, especially over a slow connection.

Several students used the system in informal tests of a pre-liminary version of the software. For the most part, the feed-back has been positive. The hearing range feature madepeople curious of what other users were saying and thegrowing and shrinking circles outside one’s hearing rangeadded a pleasant rhythm to the interface. The use of color asan identifier seemed to have worked well and no users hadtrouble identifying others on the screen - finding oneself onthe screen was not a problem either.

The history panel proved to be helpful to users trying tocatch up with the recent additions to the conversation theywere involved in. Users found it easy to understand whichmessages had been posted inside and outside their hearingranges. Nevertheless, one of the observations made by someof the users was that it was difficult to understand how themoving circles relate to the speakers’ threads on the historypanel. Because the archival threads capture the distinctionbetween messages inside and outside the hearing range butdo not show the way in which circles moved on the screen,the relationship between the two modes of the interface isnot immediately clear. We hope to make this relationshipclearer by experimenting with a 3-dimensional model forthe history panel. Users also expressed interest in the historymode as a means to revisit past online interactions.

CONCLUSION & FUTURE WORKWe have presented an overview of Char Circles, an abstractgraphical interface for synchronous conversation. One of

the main research questions in this work refers to the devel-opment of a graphical interface that creates a richer environ-ment for online discussions. Unlike existing graphicalchatroom environments, Chat Circles does not make use ofavatars. Instead, it provides graphical support of social cuessuch as turn-taking and activity level that help make onlineconversation a more transparent medium for social cuespresent in real interactions.

The next stage in this work is to build up from the funda-mental UI so as to provide users with more expressive capa-bilities.

In the conversational interface, we hope to demarcate differ-ent parts of the background in order to allow for distinctmodes of conversation. This way, the same screen will sup-port, conversations that are being recorded for archival pur-poses as well as conversations that won’t bear any records atall. We believe that this delimitation of differing sections ofthe background will happen through the discriminate use ofcolor.

We want to implement a three-dimensional (3D) version ofthe archival interface so that location as well as time andhearing range can be visualized simultaneously. Dependingon the viewpoint used to render this 3D space, one will beable to see different patterns in the conversation. By captur-ing users’ moving locations on the screen, this new versionof the Conversation Landscape will generate interesting“weaving” patterns as users rearrange their circles arounddifferent parts of the conversational interface. Users will beable to zoom in or out of the 3D model. Zooming in willallow for a closer look at individual postings whereas zoom-ing out will allow for immediate reading of both the lengthof the conversation as well as the distinct clusters of activ-ity.

We are considering adding a content-based notification sys-tem to Char Circles. This feature will operate much in themode of the “cocktail party effect” - the ability to focusone’s listening attention on a single talker among a cacoph-ony of conversations and background noise [2]. Here, a per-son’s attention is automatically geared towards aconversation because of some keyword such as the person’sname. Keywords that are of interest to the user will comeinto focus as they appear on the screen, even if they happento be located outside the hearing range of the user. This willfurther enforce the openness of the conversational interfacein the sense that people will be able to “overhear” wordscoming from other locations on the screen.

Our system is nearly at the stage when we will begin formaluser testing. As with any attempt to innovate the applicationof UIs, our approach to the interface design in Chat Circlesraises several questions about the motivations for and con-sequences of its use. One of the main questions we hope totackle is how location patterns will develop in a graphicalchatroom environment that does not make use of avatars.Studies on how people move and choose to place them-selves in urban spaces [l0] show that, there are reasons forthe patterns - no matter how awkward they may seem - thatdevelop in any public physical location. Is the same conclu-

Papers CHI 99 15-20 MAY 1999

sion possible on a location-meaningful online system? It would be interesting to keep track of the spatial distribution of people on the screen over time to understand, for exam- ple, if people prefer comer spaces as opposed to the center of the screen and, if so, why that is the case. Another inter- esting question is whether cultural differences in turn-taking styles will emerge in the archival interface.

ACKNOWLEDGMENTS Foremost, we would like to thank Rodrigo Leroux, Matthew Lee and Grace Lee for their great work in the deployment of the second version of Chat Circles. Our many thanks to Natalia Marmasse - for the help and inspiration - and Karrie Karahalios for the discussions about the project. We also thank the Digital Life and Things That Think consortia of the MIT Media Laboratory for their support of this work.

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