=Paper= {{Paper |id=Vol-485/paper-11 |storemode=property |title=Visualizing Reciprocal and Non-Reciprocal Relationships in an Online Community |pdfUrl=https://ceur-ws.org/Vol-485/paper11-F.pdf |volume=Vol-485 |dblpUrl=https://dblp.org/rec/conf/um/Sankaranarayanan09 }} ==Visualizing Reciprocal and Non-Reciprocal Relationships in an Online Community== https://ceur-ws.org/Vol-485/paper11-F.pdf
Workshop on Adaptation and Personalization for Web 2.0, UMAP'09, June 22-26, 2009




                              Visualizing Reciprocal and Non-Reciprocal
                               Relationships in an Online Community
                                       Kadhambari Sankaranarayanan, Julita Vassileva

                                     Computer Science Department, University of Saskatchewan
                                               Saskatoon, SK, S7N 5C9 Canada
                                                 {kas411,jiv}@mail.usask.ca


                         Abstract. Online communities thrive on their members’ participation and
                         contributions. There are numerous ways to visually represent information,
                         current status, power, and acceptance of members in an online community. In
                         this paper we present a design of a visualization representing reciprocal and
                         non-reciprocal relationships among users, which emphasizes and hopefully
                         triggers common bond in the community. Our future goal is to see whether the
                         visualization triggers higher participation in an online community called
                         “WISEtales”, which currently is mostly based on common identity. If our
                         hypothesis is confirmed, it will present one of the few examples of successful
                         community whose members associate both by common identity and common
                         bond.


                         Keywords: Information visualization, social visualization, visual design.



                  1 Introduction
                  Designing a visualization tool for an online community is a great challenge in the
                  field of visualization research. During its existence an online community produces
                  huge amount of content and it becomes difficult for the user to navigate and find the
                  information that they are looking for. It also becomes complex to understand the
                  evolution and the type of relationships that exist among members. “Social
                  visualizations are one way to “describe” our online environments and make
                  interaction patterns and connections salient” [1]. Any visualization should evoke
                  meaning beyond direct mapping of data otherwise it is said to be misleading. Social
                  visualizations have some evocative quality [2].
                            WISETales is an online community for Women in Science and Engineering.
                  This community has been developed by a graduate student, Zina Sahib, as one of the
                  projects of the NSERC/Cameco Chair for Women in Science and Engineering for the
                  Prairies, Dr. Julita Vassileva. This community is specially designed to allow women
                  who are underrepresented in these areas to share their personal stories. This is a
                  virtual channel to share emotion, experience and provide support to other women. It
                  helps women to overcome the generation gap and isolation. Generally women in these
                  fields are very busy and achieving active participation is a great challenge. So to
                  motivate their participation is vital for the existence of the community. In order to
                  overcome this problem, we propose to use a visualization of user relationships that
                  can motivate users to contribute and reach a critical mass of active users.




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                  2 Literature Survey
                  Our research covers the area social comparison and motivational theories in
                  psychology, organizational theories: common identity and common bond theory, and
                  social visualization.

                  Theories of Motivation in Psychology
                  According to the cognitive evaluation theory there are two motivation systems -
                  intrinsic and extrinsic - that corresponds to two kinds of motivators. Intrinsic
                  motivators are: achievement, responsibility and competence, motivators that come
                  from the actual performance of the task or job, the intrinsic interest of the work.
                  Intrinsically motivated individuals perform for their own achievement and
                  satisfaction. Extrinsic motivators are: pay, promotion, status, power, better working
                  conditions, feedback that comes from a person’s environment, controlled by others
                  [3].
                            One of the theories from social psychology that is used to explain human
                  motivation is the social comparison theory [4]. Social comparison consists of
                  comparing oneself with others in order to evaluate or to enhance some aspects of the
                  self. Cognitive and emotional responses to comparison have been extensively studied,
                  but less is known about the effects of comparison on behavior. There is very little
                  guidance about how people compare themselves in an online community. Sun and
                  Vassileva [5] examined the effect of making individual reputation visible in an online
                  system for sharing research papers and found out that displaying reputation increased
                  contributions but some users contributed low quality content simply to achieve higher
                  reputation. A study on the MovieLens movie rating system was conducted [6] by
                  sending email newsletters to users indicating whether their contributions to the
                  community were above or below or about average when compared to others which
                  involved men and women. Women reported being motivated to contribute more
                  ratings when they were told they had rated approximately the same number of movies
                  as others and men were motivated to contribute more when they were told they had
                  rated fewer than others. Members who received a newsletter that encouraged social
                  comparison rated more movies than other members who received a newsletter which
                  didn’t encourage social comparison. Upward comparisons were most motivational in
                  this system. However, introducing social comparison into a community might be
                  risky. It could work and increase member participation or it might not work and
                  reduce member’s contributions. Competitive and gaming members like to be
                  compared with other members, but others may find it discouraging and de motivating.
                  People who are by nature more competitive (stereotypically, men are believed to be
                  more competitive than women) are more likely to be motivated by the upward social
                  comparison condition. It is arguable if women are less competitive, and especially if
                  women in the science and engineering field are less competitive. They may respond
                  very well to social comparison. However, in this research we would like to
                  experiment with creating a visualization that emphasizes relationships, based on the
                  common bond theory. It is generally considered a bad idea to mix motivations (e.g.
                  extrinsic and intrinsic motivation) in the same system. Similarly, we fear that mixing
                  social comparison with common bond may negate each other and it may be




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                  impossible to observe any change in user participation, or it will be hard to attribute
                  the change, if there is any.

                  Common Identity and Common Bond:
                  Community design affects how people can interact, the information they receive
                  about one another and the community, and how they can participate in community
                  activities. There are two theories of group attachments that have been linked to design
                  decisions on online communities [7]. The common identity theory makes predictions
                  about the causes and consequences of people’s attachment to the group as a whole
                  and the common bond theory makes predictions about the causes and consequences of
                  people’s attachments to individual’s group members.
                  The causes of common identity are social categorization, interdependence and
                  intergroup comparison.
                  Social categorization: it happens when one creates a group identity by defining a
                  collection of people as members of the same social category [8][9]. Interdependence:
                  Groups whose members are cooperatively interdependent tend to become committed
                  to group [7]. Intergroup comparison: People who define and categorize themselves as
                  members of a group compare themselves with other groups [10] and raising the
                  salience of out-groups intensifies people’s commitment to their in-groups. The causes
                  of common bond are social interaction, personal information, and personal attraction
                  through similarity.
                  Social interaction: Social interaction provides opportunities for people to get
                  acquainted, to become familiar with one another, and to build trust. As the frequency
                  of interaction increases, their liking for one another also increases [11]. Personal
                  Information: Opportunities for self-disclosure when members exchange personal
                  revealing information about the self becomes a cause or consequence of interpersonal
                  bonds [12]. Personal attraction through similarity: People like others who are similar
                  to them in preferences, attitudes and values, and they are likely to work or interact
                  with similar others. Similarity can create common identity as well as interpersonal
                  bonds [7].

                  Comparison of Common identity and Common bond:
                  Some identity-based communities shift eventually toward supporting and promoting
                  interpersonal connections among members. For example, Flickr.com was established
                  as an online application for photo management and sharing but it later evolved into a
                  community where people not only share, tag, and comment on photos, but also join
                  groups and interact in its public and private forums[7].
                           Bond based communities help newcomers to connect with existing members,
                  to join group interactions, and to form lasting relationships with a subset of
                  community members. Bond-based communities care more about people-finding than
                  information finding, making it easy to find and meet specific members through
                  directory or personal profile search page [7]. These communities encourage personal
                  relationships, and their introductory material often encourages participants to post on
                  a wider range of topics [7]. As compared to common identity, in common bond based
                  communities newcomers feel isolated and become confused to see off topic
                  discussions among members. But in our research since all discussions would be based
                  on members stories, newcomers would be able to understand every part of the




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                  discussion once the corresponding story is read and it would not be off putting for
                  them.

                  Reciprocation
                  In Common Bond based community people develop relationships with other members
                  and that is what ties them to the community which cannot be expected from Common
                  Identity based community. People often help others with the expectation that their
                  help would be compensated or reciprocated, either by those they have helped or by
                  the group as a whole [13] [14]. Thus reciprocation can happen at a dyadic or at
                  community level. In case of common bond there is direct reciprocity and in case of
                  common identity there is general reciprocity. Social psychologists have found that the
                  urge to reciprocate is deeply ingrained [15]. Sellers and buyers on eBay usually
                  reciprocate in their ratings of each other [16] Voting on web sites is sometimes done
                  in the context of reciprocity [17]: if you rate my story highly I will rate yours highly.
                  Networks of reciprocity are highly motivating, and encourage participants to maintain
                  an awareness of the community that surrounds them [18].A community designed on
                  the basis of common identity is said to be more stable when compared to community
                  designed on the basis of common bond [7]. This is because, in common bond based
                  community, if a member leaves the group, the friends associated with that member
                  would also likely leave the group or become passive. This does not occur in
                  community designed on the basis of common identity. WISEtales is designed on the
                  basis of common identity theory, so we can expect that it would be more stable.
                  Representing relationships in a common identity based community encourages
                  common bond. As very little research has been done on the coexistence of identity-
                  based and bond-based attachment, this encourages us explore combining cues that
                  stimulate both kinds of attachment. According to Milgrams [19] and Zajonc[20],
                  visually representing people in an online group formed personal attachment to them
                  even without communicating with each other. Visualization of actual communication
                  flow among community members can create bond between friends of friends by
                  helping people fill in gaps [7]. Making contributions visible in a community as a
                  whole leads to some extent of recognition of the member’s contributions. The nature
                  of online interaction means that helpful acts are more likely seen by the group as a
                  whole. The following features encourage reciprocity: ongoing interaction, identity
                  persistence, and knowledge of previous interactions, since they promote the creation
                  and importance of reputation within a community. So visualizing reciprocal and non
                  reciprocal relationships might help members to recognize their current position in the
                  community.

                  Social Visualization
                  Visually representing information enables users to see data in context, observe
                  patterns and make comparisons [21]. Visualization techniques are important aids in
                  helping users and researchers understand social and conversation patterns in online
                  interactions [22]. A data portrait of an online community can give overall information
                  about each other and the overall social environment [23]. “Social visualization is
                  defined as the visualization of social data for social purposes” [24]. Social
                  visualization is a sub category of information visualization. It focuses on people,
                  groups, conversational patterns, interactions with each other and relationships with




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                  each other and with their community. Social networks are said to be a form of social
                  visualization because they have two types of organization patterns namely social
                  groups and social positions [25]. There are various techniques to represent a group of
                  people in an online community. Most approaches use nodes to represent individuals
                  and arcs between the nodes to represent connections between them. Real social
                  networks have dense interconnections between people.
                  Vizster is a visualization system for playful end-user exploration, navigation of large-
                  scale online social networks to increase awareness of the community. Heer et al. [21]
                  found out by observing through Vizster visualization that groups of users, spurred by
                  stotytelling of shared memory spent more time in exploring stories and asked deeper
                  analysis questions than other members. Further Vizster’s visual community analysis
                  provided help to users who could construct and explore higher-level structures of their
                  online communities. Visualizations provide not just an analysis tool for social science
                  researchers. Heer et al. [21], through the “sense.us” visualization for group
                  exploration of demographic data found out that combining conversation and visual
                  data analysis helps people to explore data broadly and deeply. When visualizing
                  conversations, it should evoke an appropriate intuitive response to represent the feel
                  of the conversation as well as depict its dynamics [26]. Coterie, a visualization tool
                  for Internet Relay Chat (IRC) shows the activity of the participants and also the
                  structure of conversation. It highlights active participants and conveys the vitality of
                  discussion [26]. PeopleGarden is a visualization tool for representing member’s
                  participation on a message board. It uses flower and garden metaphor. From this
                  anyone can easily perceive an individual’s active role or long-time lurker [26]. The
                  Loom Project is an evocative semantic visualization for Usenet newsgroups. It is used
                  to depict the leaders and provocateurs. There are people who post frequently and are
                  often replied to in a positive way. This visualization distinguishes them from other
                  frequent posters such as trolls (deliberate troublemakers), automatic newsfeeds, and
                  the excessively verbose [26]. IBlogVis [27] is a visualization tool for browsing blog
                  archives. It provides an overview of posted blog articles over time with their length
                  and number of comments received to help users to find the interesting articles in the
                  blog at a glance and to ease exploration and navigation. Social network visualization
                  for blogspace revealed that topic-oriented blogs had more interconnections and
                  reciprocation than most popular blogs [28]. Webster and Vassileva [29] explored in
                  the context of a discussion forum, if a visualization of the reciprocity of a user’s
                  relationships with other users would motivate the user to engage in more reciprocal
                  relationships and showed that it indeed does so for active members, though it doesn’t
                  increase the level of participation in general. Chin and Chingel’s [30] visualization for
                  blogspace show links for suggesting a social relationship among the bloggers. Social
                  visualization is expected to activate social norms of behavior, encourage social
                  comparison and reciprocity. According to Vassileva and Sun [5] motivational
                  visualization effectively increased awareness of community and encouraged social
                  comparison and as a result contribution to the community increased. We propose to
                  incorporate a motivational visualization to increase participation by stimulating social
                  bond among members and evoking reciprocity among between pairs of users, as well
                  as a gentle social comparison in terms of number of reciprocated relationships.




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                  3 Proposed approach
                  To achieve the goal of increasing active participation, we propose designing a system
                  which incorporates visualization techniques to motivate user participation by evolving
                  their relationships with other members in the online community.

                  Motivation
                  Our hypothesis is that an appropriately designed visualization can stimulate
                  motivational and organizational mechanisms that lead to more active contributions by
                  users to their community. Our approach is to encourage intrinsic motivation
                  (according to the cognitive evaluation theory from psychology) and the common bond
                  theory (from organizational studies). The objective of our research would be to model
                  the evolution of relationships based on data from user interactions, for example
                  reading and writing stories or giving comments and to design a visualization of these
                  relationships which will serve as a tool to motivate users to contribute more towards
                  their group. Our visualization would display these relationships between users so that
                  it would be easy for the user to understand his/her current position in the community.
                           We have chosen the WISEtales community as a test bed for our approach. In
                  bond-based community people engage in direct reciprocity. So the visualization will
                  reveal which are reciprocal and non reciprocal relationships. Reciprocity increases
                  when members interact repeatedly. People help others with the expectation of having
                  their help returned by that individual or the group as a whole [13] [14]. Returning
                  favors is are acts of reciprocation. Yet it is not clear if being aware of the reciprocity
                  of their relationship, and the direction of non-reciprocal relationships (who “owes”
                  favors to whom) will motivate users to reciprocate more frequently and thus
                  contribute more. This is what we would like to test. In this community, reciprocation
                  happens when a member reads a story or post comments to a story submitted by
                  someone else. Other actions, such as posting a story to one’s Facebook profile,
                  forwarding it to a friend or checking the story, author’s profile may also be considered
                  as acts of reciprocation.

                  Visualization Design
                  To make the visualization more likeable for women, a flower garden metaphor is used
                  (see Figure 1). Each user is represented in circular node with his/her name written in
                  it. The node is surrounded by arcs (visualized as leafs) corresponding to relationships
                  with other users. Each arc (leaf) has the corresponding user names and different color
                  to indicate reciprocal and non reciprocal relationships. The stronger and thicker the
                  color then the reciprocation is said to have happened between the users. This helps the
                  users to understand how many reciprocal and non reciprocal relationships they and
                  the other users are involved in. The node of the viewer will be highlighted among the
                  other circular nodes, so that he / she can compare his/her relationships with those of
                  the other users. If a user has received lot of comments from a particular user and has
                  not been aware of that before, the visualization will make him/her realize that he/she
                  “owes” that user some attention, and that he/she needs to contribute something to the
                  other user. Also the realization that other users are viewing the same visualization and
                  will be aware of the lack of reciprocation from the user to others will add social
                  pressure to behave according to community norms (a form of social comparison).




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                           Thus a social visualization showing the users’ relationships with other users
                  could be motivational, if users become aware about the number and balance of their
                  reciprocal and non reciprocal relationships with other users expressed through the
                  visual effects. They would get an overall idea about the other members’ contributions,
                  would be interested to read stories contributed by active members, post comments and
                  also spread the word about interesting stories. The visualization will be dynamic – it
                  will change when new members sign in and when new comments are given and
                  reciprocal actions performed. The visualization is intuitive but not interactive since
                  previous research by [5] showed that interactive features were rarely used. It is not
                  customizable by the users.
                  One can see in Figure 1 that there are three distinct colors used to represent reciprocal
                  and non reciprocal relationships. The more petals a flower has, the more the active the
                  member is. The dark green color leaf is used to represent reciprocation among users;
                  the medium green color leaf is used to represent comments received from other users
                  and the light green color leaf is used to represent comments given to other users.
                  Viewers perceive colors differently but experimental evidence shows that
                  relationships between colors are universal and are free from individual and cultural
                  differences [31]. According to [31], “People can make consistent evaluation of the
                  magnitude of any given experience of colors based on the type of interaction among
                  colors. People respond to the relationship among colors”. The colors chosen for this
                  visualization are of analogous ordering. Such kind of ordering is more lively than
                  monochrome and is stable in arrangement than non analogous ordering or
                  complementary parings. Each member is represented as circular node in brown color.
                  The person who is engaged in most reciprocal relationships is placed in the center and
                  other members are placed surrounding it. According to [32] “Varying shapes of nodes
                  is used to denote different characteristics of members in the graph; the location of the
                  node is used to denote the valuable marker for understanding the structure in the
                  network. Centrality in a group is a useful indicator that the participant plays a key role
                  in the group [33]. Each leaf has a rounded and a very sharp edge. The sharp edge is
                  placed outside and is rotated to point to the direction of the corresponding individual’s
                  node whose name is mentioned on the respective leaf (along the arc connecting the
                  nodes representing the users). The reason is to give an easy navigation and sense of
                  direction for the user to find their relationship partners in the visualization.
                           Reciprocation between two members is currently calculated by the number
                  of views and comments to each other’s story. For example, in Figure 1 it can be seen
                  that Karthik’s node is placed in the center as it has a higher number of reciprocated
                  relationships when compared to other nodes. The members with fewer reciprocated
                  relationships are placed surrounding the central person. The other members with very
                  few relationships are placed in the outer circle. All nodes in the graph are created
                  using concentric circle algorithm. Placing the leaves in the corresponding direction of
                  the node is not a trivial task. It is done by using some rotation measures and graphics
                  algorithm to generate the graph.
                           This visualization does not include any connection lines between nodes.
                  “The fewer the number of lines crossing, the better the sociogram” [32]. This is
                  because lines between nodes increases complexity and decreases the beauty of the
                  visualization. The visualization comes with a key to help users indentify which colors
                  represent which type of relationship.




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                     Figure 1: Visualization of reciprocal and non-reciprocal relationships for logged in
                                                 members of WISETales.

                  Implementation
                  The technology used to design the visualization is Flash and Flare. Flare is mainly
                  used for web content visualization and is highly scalable. WISETales is built on
                  Drupal, PHP and MySql technologies. Flash can easily integrate with PHP and
                  MySql. A link to the visualization will be implemented in WISETales website. As
                  soon as the member of WISETales website logs in he/she would be able to click on
                  the link to visualization to see it. In the visualization, the area of the corresponding
                  member who is currently viewing the visualization would be highlighted in pink to
                  show his/her current position in the group. Also when they click on their node all the
                  nodes and leaves that are related to them representing reciprocal and non-reciprocal
                  relationships would also be highlighted in the visualization. User of the visualization
                  can also click on the particular flower to scale to get the information of a particular
                  person clearly.

                  Prototype Evaluation
                  A medium fidelity prototype of the visualization using Flash was developed and
                  tested to assess whether the visualization of reciprocal and non-reciprocal relationship
                  conveys the correct information to the user, whether they were able to understand the
                  visualization clearly. The evaluation tool used for the medium fidelity prototype was a
                  questionnaire. The question type used were Scalar-Likert scale because it measures
                  opinions, attitudes and beliefs. Each question asks the user to judge a specific
                  statement on a numeric scale with extremes 4 –indicating agreement and 1 –




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                  indicating disagreement with a statement. I also used open questions to get specific
                  answers and to give room for user suggestions. The questionnaire was implemented
                  using the SurveyMonkey.com tool.
                           The representative users for the evaluation of the medium fidelity prototype
                  were 12 graduate students from our MADMUC lab at the University of
                  Saskatchewan. The link to the prototype as it ran on a server and a link to the
                  questionnaire were sent to each participant in an email. The most serious concerns
                  users had were related to the scaling of the visualization, as can be seen in Figure 2.
                  We need to work on the scalability, perhaps through creating fish-eye views or a
                  magnifying glass effect.




                            Figure 2: Results of the evaluation of the visualization prototype.

                  Future evaluation of the visualization
                  Our hypothesis is that visualizing reciprocal relationships would increase the users
                  understanding of their community, will encourage common bond and will ultimately
                  increase participation. We chose to evaluate the effect of proposed visualization in
                  WISEtales by using three different versions (two control versions and experimental
                  version) of the community with two different groups of users. Fifteen members would
                  participate in each version. The experimental version would have the proposed
                  visualization. The first control version will have no visualization and the second
                  control version will have a different visualization (one developed by Zina Sahib) and
                  based on common identity theory, showing only the type of contributions, not the
                  users. All members would be given a period of one month to use the community with
                  their respective version. In the next two months, the groups will rotate their versions,
                  so that each group gets exposure with each version. The contributions from members
                  in experimental version and members in control version and their reciprocal
                  relationship with other members would be collected and analyzed. A questionnaire
                  will also be used to collect qualitative data about the users understanding of the
                  structure of the community, the importance of individuals in it; as well as their
                  feelings of attachment to particular individual or the community as a whole.




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                  4 Conclusions
                  We propose to use a motivational visualization aimed at encouraging common bond
                  in a common identity based community and see the effects on user contributions. We
                  want to test if particular visualization design, showing how users are engaged in
                  reciprocal and non-reciprocal relationships with each other could stimulate
                  reciprocation and motivate higher user participation. If our hypothesis turns to be true
                  this may provide empirical evidence about the possibility of successful and stable co-
                  existence of common identity based community and common bond based community
                  within one group.


                  References

                  1. Karahalios, K.G 2006 ‘Social Visualization: Exploring Text, Audio, and Video Interaction’.
                     CHI April 22-27 ACM.
                  2. Boyd, D., Lee, H-Y, Ramage,D. and Donath, J. Developing legible visualizations for online
                     social spaces. In Proceedings of the Hawaii International Conference on System Sciences.
                     (Jan. 7-10, 2002, Big Island, Hawaii).
                  3. Theories of Motivation. http://www.analytictech.com/mb021/motivation.htm
                  4. Festinger, L. A Theory of Social Comparison. Human Relations, 7, 1954.
                  5. Vassileva,J and Sun,L.(2007) Using Community Visualization to Stimulate Participation in
                     Online Communities. E-Service Journal, 6 (1), 3-40. (special Issue on Groupware).
                  6. Harper, M.F., Frankowski, D., Drenner, S., Ren, Y., Kiesler, S., Terveen, L., Kraut, R.,
                     Riedl, J Talk Amongst Yourselves: Inviting Users To Participate In Online Conversations,
                     2007 IUI, Jan 28-31, ACM.
                  7. Ren ,Y., Kraut, R., and Kiesler, S. 2007. Applying Common Identity and Bond Theory to
                     Design of Online Communities. ACM. Syst. 15, 5 (Nov. 1993), 795-825.
                     DOI:10.1177/0170840607076007, http://oss.sagepub.com/cgi/content/abstract/28/3/377
                  8. Turner, J.C. 1985 ‘Social categorization and the self-concept: A social cognitive theory of
                     group behavior’ in Advances in group processes: Theory and research, Vol. 2. E. J. Lawler
                     (ed), 77-122. Greenwich, CT:JAI Press.
                  9. Turner, J. C., M.A.Hogg, P.J. Oakes, S.D.Reicher, and M.S. Wetherell 1987 Rediscovering
                     the social group: A self-categorization theory. Oxford; Blackwell.
                  10. Tu, M. A., and D. J. Terry 2000 ‘Social identity and selfcategorization processes in
                     organizational context’. Academy of Management Review 25/1: 121–140.
                  11. Cartwright, D., and A. Zander 1953 ‘Group cohesiveness: Introduction’ in Group
                     dynamics: Research and theory. D. Cartwright and A. Zander (eds). Evanston, IL: Row
                     Peterson.
                  12. Collins, N. L., and L. C. Miller 1994 ‘Self-disclosure and liking: A metaanalytic review’.
                     Psychological Bulletin 116/3: 457–475.
                  13. Blau, P.M. 1964 Exchange and power in social life. New York: John Wiley.
                  14. Emerson, R.M. 1972 ‘Exchange theory: A psychological basis for social exchange’ in
                     Sociological theories in progress (Vol. 2,pp. 38-87). J. Berger, M. Zelditch and B. Anderson
                     (eds). Boston: Houghton Mifflin.
                  15. Cialdini, R. B. Influence: Science and practice (4th ed.). Boston: Allyn & Bacon. 2001.
                  16. Resnick,P and Zeckhauser,R., Trust Among Strangers in Internet Transactions: Empirical
                     Analysis of eBay’s Reputation System (2002). The Economics of the Internet and
                     Amsterdam, Elsevier Science. Pp. 127-157.




                                                               108
Workshop on Adaptation and Personalization for Web 2.0, UMAP'09, June 22-26, 2009




                  17. Dellarocas, C. N., Fan, M. N. and Wood, C. A., Self-Interest, Reciprocity, and Participation
                     in Online Reputation Systems (February 2004). MIT Sloan Working Papers No. 4500-04.
                  18. Sadlon, E., Sakamoto, Y., Dever, H. J., Nickerson, J. V. (2008). The Karma of Digg:
                     Reciprocity in Online Social Networks In Proceedings of the 18th Annual Workshop on
                     Information Technologies and Systems.
                  19. Milgram,S. 1997. ‘The familiar stranger: An aspect of urban anonymity’ in The individual
                     in a social world: Essays and experiments. S. Milgram (ed.), 51-53 Reading, MA: Addison-
                     Wesley.
                  20. Zajonc, R. B. !986 ‘ Attitudinal effects of mere exposure’. Journal of Personality and Social
                     Psychology 9/2, PT. 2: 1-2
                  21. Heer,J., Viegas, F.B and Wattenberg, M. 2009 ‘Voyagers and Voyeurs: Supporting
                     Asynchronous Collaborative Visualization’. Proceeding of the SIGCHI Conference on
                     Human Factors in Computing Systems, April 2007. VOL. 52, Communications of the ACM.
                  22. Viegas,F.B., danah boyd, Nguyen, D.H., Potter, J., and Donath,J. Digital artifacts for
                     remembering and storytelling:PostHistory and social network fragments. In Proceedings of
                     Hawaii International Conference on System Sciences (HICCSS) (2004), 105-111.
                  23. Xiong, R and Donath,J (1999). “PeopleGarden: Creating Data Portraits for Users” MIT
                     Media Laboratory, Cambridge ACM.
                  24. Karahalios K.G and Viegas F.B. “Social Visualization: Exploring Text, Audio, and Video
                     Interaction” CHI 2006, ACM.
                  25. Freeman, L.C., Visualizing Social Networks. Journal of Social Structure, 2000.
                  26. Donath,J.2002 ’A Semantic Approach to Visualizing Online Conversations’ (Vol. 45).
                     Communications of the ACM.
                  27. Indratmo, Vassileva J and Gutwin C, 2008 ‘Exploring Blog Archives with Interactive
                     Visualization’, ACM (May 28-30).
                  28. Herring, S.C., Kouper, I., Paolillo, J.C., Scheidt, L.A., Tyworth, M., Welsch, P., Wright, E.,
                     and Yu, N. Conversations in the blogosphere: an analysis “from the bottom up.” In Proc.
                     HICSS-38, 2005
                  29. Webster,A and Vassileva,J ., Visible Relations in Online Communities, in Adaptive
                     Hypermedia and Adaptive Web-Based Systems, Dublin, Ireland, Springer LNCS 4018, 223-
                     233.
                  30. Chin, A. and Chignell, M. A social hypertext model for finding community in blogs. In
                     Proc. HYPERTEXT, 11-22, 2006.
                  31. Jacobson, N and Bender, W. “Color as a determined communication”, IBM Systems
                     Journal, VOL 35, NOS 3&4, 1996.
                  32. Moreno, J.L. Who Shall Survive? Beacon, NY: Beacon House, Inc. 1953.
                  33. S.Wasserman and K.Faust. Social Network Analysis. Cambridge University Press, 1994.




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