UNIVERSITY OF OSLO Department of Informatics Social Navigation on the Social Web Unobtrusive Prototyping of Activity Streams in Established Spaces Master thesis Eivind Uggedal August 2008 SOCIAL NAVIGATION on the SOCIAL WEB m Unobtrusive Prototyping of Activity Streams in Established Spaces Eivind Uggedal August óþþ Submitted in partial fulllment of the requirements for the degree of Master of Science to the Department of Informatics Faculty of Mathematics and Natural Sciences University of Oslo is thesis was typeset using the LATEX typesetting system originally developed by Leslie Lamport, based on TEX created by Donald Knuth. e body text is set Õó/Õ¦.¢pt on a óäpc measure with Minion Pro designed by Robert Slimbach. is neohumanistic font was rst issued by Adobe Systems in ÕÉÉ and have since been revised. Other fonts include Sans and Typewriter from Donald Knuth’s Computer Modern family. Typographical decisions were based on the recommendations given in Ce lements of Bypographic >tyle by Bringhurst(óþþ¦). e use of sidenotes instead of footnotes and gures spanning both the textblock and fore-edge margin was inspired by eautiful vidence by Tue(óþþä). e guidelines found in Ce Oisual isplay of :uantitative nformation by Tue(óþþÕ) were followed when creating diagrams and tables. Colors used in diagrams and gures were inspired by the >ummer ields color scheme found at http://www.colourlovers.com/palette/399372 a ABSTRACT Social navigation usage on the Social Web were studied by conducting content analyzes to see how prevalent such navigation is now compared to the Web’s earlier years. e common characteristic of the types of social navigation we found in these sites were the reliance on peers for the information used in the navigation process. We therefore built on existing denitions of social navigation an provided our own deni- tion which emphasized the essentialness of peers in the web site one is navigating in. We found activity streams – chronological listings of what all the individuals one is particularly interested in have recently been doing on a web site – to be an interesting and seemingly useful technique of social navigation. A prototype of activity streams were built on top of the Urørt web site to test the usefulness of such a social navigation technique in a real world two-group experiment with a pre-post setup. e experiment results were somewhat inconclusive, partly because of high non-accomplishment rates and some ambiguous results. e high non-accomplishment rates seemed to have a strong connection to the technical prototype plattform we used as participants had a hard time trying to install the necessary soware. i CONTENTS Abstracti Contents iii List of Figuresv List of Tables vi Preface vii Õ IntroductionÕ Õ.Õ FocusÕ Õ.ó Motivationó Õ.ì Objectiveì Õ.¦ Contributionsì Õ.¢ Outline¦ Social Navigation on the Social Web ó Introducing Social Navigationß ó.Õ Literature Searchß ó.ó Navigation ó.ì SocialityÉ ó.¦ Social Navigation Õì ó.¢ Forms of Social Navigation Õä ó.ä Is Social Navigation Valuable? ìþ ì Social Navigation on Flickr & Facebook ìì ì.Õ Method ìì ì.ó Results ìß ì.ì Discussion ¦ì ì.¦ Generalizability and Validity ¦¦ Unobtrusive Prototyping of Social Navigation ¦ Implementation of an Unobtrusive Prototype ¦ß ¦.Õ Building on Top of the Web ¦ß iii ¦.ó Design ¦ ¦.ì Process ¢¦ ¦.¦ Architecture ¢ä ¦.¢ Performance ä¢ ¦.ä Source Code ä¢ ¢ Empirical Study of a Social Navigation Prototype äß ¢.Õ Research Problems and Hypotheses äß ¢.ó Method äÉ ¢.ì Results ßä ¢.¦ Discussion ¢.¢ Generalizability and Validity Éä Summary ä Conclusion ÕþÕ ä.Õ Lessons Learnt ÕþÕ ä.ó Future Work Õþó Bibliography Õþ¢ Appendices A Content Inventory Õó¢ A.Õ Flickr Õó¢ A.ó Facebook ÕìÕ B Selection of ird Party Soware Õ¦Õ B.Õ Prototype Soware Stack Õ¦Õ B.ó Development Tools Õ¢ì C Questionnaires Õ¢ß C.Õ Pretest Survey Õ¢ß C.ó Follow-up Survey Õ¢ C.ì Posttest Survey Õ¢ D Source Code ÕäÕ D.Õ Unobtrusive Social Navigation Prototype for Urørt ÕäÕ D.ó Reddit Collaborative Filtering Algorithm ÕäÕ D.ì JavaScript Comment Stripper Õäó D.¦ Shell File and Directory Hierarchy Õäó iv LISTOFFIGURES ó.Õ Blogroll Õß ó.ó Research Journal Tag Cloud óþ ó.ì Trailre Trail óì ó.¦ Collaborative Filtering at Reddit ó¢ ó.¢ Recommendations at Amazon ó ó.ä CoWeb Contextual Cues óÉ ó.ß CoWeb Global Cues óÉ ó. virtPresenter Timeline ìþ ì.Õ Flickr Welcome Page ìä ì.ó Flickr Photo Detail Page ìä ì.ì Flickr Photo Meta-data ìß ì.¦ Flickr Tag Cloud ì ì.¢ Flickr Tag Cluster ìÉ ì.ä Flickr Geotagging ¦þ ì.ß Facebook News Feed ¦Õ ì. Facebook Prole ¦Õ ì.É Facebook Hyperlink Sharing ¦ó ì.Õþ Facebook Photo Tagging ¦ì ¦.Õ Hoodwink.d Comments ¦ ¦.ó Urørt Main Page ¢þ ¦.¦ Socialthing! Activity Stream ¢Õ ¦.ì FriendFeed Activity Stream ¢Õ ¦.¢ Urørt Activity Stream ¢ì ¦.ä Urørt Favorite List ¢¦ ¦.ß Prototype Class Diagram äì ¦. Prototype Server File Hierarchy ä¦ ¢.Õ Experiment Overview ßÕ ¢.ó Experiment Non-Achievement Rates ßß B.Õ JavaScript Library Comparison Õ¦¢ B.ó Prototype Architecture Õ¢ó v LIST OF TABLES Õ.Õ Social Navigation in Academiaó ó.Õ Literature Databases ¦.Õ Prototype Data Structure ä¦ ¦.ó Retrieval Time and Speed ä¢ ¦.ì Prototype Source Code Statistics ä¢ ¢.Õ Statistical Symbols äß ¢.ó Respondents Gender and Age, Between Groups ß ¢.ì Respondents Firefox and Urørt Usage, Between Groups ß ¢.¦ Up-to-date on Favorites’ Activities, Between Groups ßÉ ¢.¢ Up-to-date on Favorites’ Activities, Within Groups þ ¢.ä Up-to-date on Specic Activities, Between Groups Õ ¢.ß Up-to-date on Specic Activities, Within Groups ó ¢. Perceived Usefulness, Between Groups ì ¢.É Perceived Ease of Use, Between Groups ¦ ¢.Õþ e Prototype as a Standard Feature, Between Groups ¢ ¢.ÕÕ Up-to-date on Activities Frequency, Between Groups ¢ ¢.Õó Up-to-date on Activities Frequency, Within Groups ä ¢.Õì Usage of Prototype Frequency, Between Groups ä ¢.Õ¦ Number of Favorites, Between Groups ß ¢.Õ¢ Number of Favorites, Within Groups ß ¢.Õä Prototype Installation Success ¢.Õß Prototype Installation Drop O A.Õ Variable Listing for Flickr Õó¢ A.ó Content Inventory of Flickr Õóä A.ì Variable Listing for Facebook ÕìÕ A.¦ Content Inventory of Flickr Õìó B.Õ ird Party Soware Versions Õ¢ì vi PREFACE is is a master thesis of äþ creditsÕ in the eld of Informatics. It was Õ. Prescribed to one year of full time written for the Design of Information Systems research group at the De- study. partment of Informatics, Faculty of Mathematics and Natural Sciences, University of Oslo. Asbjørn Følstad at «±u was of great help in building the research design used for our real world experiment. He did also accept our work as part of the §uh§o project where we were able to obtain founding. Morten Skogly at § Urørt was helpful with providing information about their web site and recruiting participants to our experiment. Andreas Dieberger, Peter Brusilovsky, and Robert Mertens was help- ful with giving us permission to freely use illustrations from their pub- lished articles. Last but not least my supervisor, Gisle Hannemyr, deserves credit for his guidance and thoughtful input during the majority of the master thesis process. anks to Tone Bratteteig for helping me out when Gisle was unavailable. Eêo UuoZ Oslo, Norway August óþþ vii INTRODUCTION e web has come a long way since its inception when it functioned as a global interconnected system for document sharing amongst researchers (Berners-Lee et al., ÕÉÉó, p. ó). We’ve seen the coming of an increasingly more social web as “the digital domain has seen a signicant growth in the scale and richness of on-line communities” (Backstrom et al., óþþä, p. ¦¦). ere have been an increase from ÕÛ to ¦¢Û in blog usage by Õ 1 the general public in an Õ month period from óþþ¢ to óþþß. It has been argued that web citizens’ familiarity with blogging laid the groundwork Õ. Represented with a total of ä,¢¦¢ for the explosion we are seeing in user participation in web communities respondents to a survey conducted (Weiss, óþþ¢, p. óþ; Beer and Burrows, óþþß, paragraph ó.ó). in Canada, France, Germany, Japan, the United Kingdom, and the At the same time advances in hardware and web development tools United States by Rosa et al.(óþþß, have made it easier and cheaper to create new web sites. We’re now ch. Õ, p. ó). seeing an abundance of new oerings in this eld. It has been argued that many of the concepts this modern web brings are evolutionary ó. Knuth(óþþß) also believes in- instead of revolutionary (Yakovlev, óþþß, p. ¦¢). Treese(óþþä, p. Õß) also novation in computer science is witnesses a continuous evolution, but with exploratory innovations as incremental: “I rmly believe that ó computer science advances by he notes that most technological changes are incremental. Weiss(óþþ¢, thousands of people solving small p. Õ) have noticed this trend: problems, which go together and create a massive edice. Every year When we consider a hot, buzz-worthy Web site of the new Internet evolu- that goes by, hardly anything is done tion [...] they are at the same time incredibly innovative and yet – not. that appears to be a milestone wor- thy of mass attention; yet aer ve or ten years pass, the whole eld has What we’re experiencing today with the World Wide Web and so- changed signicantly”. cial/collaborative soware systems was envisioned several decades ago by Licklider and Taylor(ÕÉä) and Bush(Õɦ¢). During the initial studies of our research we frequented many of these modern web sites. Our impression is that this area of the web infamously coined Web ó.þ – an increment in version opposed to the age when the Web was in its infancy – is bringing interesting innovations.