Proceedings of the Fourth International AAAI Conference on Weblogs and Social Media Preface ciology, and communication, featuring three speakers. James W. Pennebaker’s talk will address the fact that most language-based computer programs analyze content-heavy words (such as nouns and regular verbs) and throw out “junk” words (such as pronouns, prepositions, and articles) to understand people’s thinking, buying, searching, and other behaviors. He will present a series of recent studies that point to the role of junk words in identifying personality, depression, status, honesty, group cohesiveness, and other individual and group behaviors. S. Craig Watkins’s talk will show how young people’s participation in Facebook is actually more complex than the popular images and myths suggest. Drawing from both survey data and in-depth interviews with current college students and recent college graduates Watkins considers how the use of Facebook evolves across the young life-cycle. Nicole Ellison’s talk will present research examining how people use the Internet to engage in self-presentation, form and maintain relationships, and garner social capital benefits. The talk will present two new streams of research: one examining the ways in which people use Facebook to connect with others and access social support and the other exploring online dating participants’ perceptions regarding acceptable and unacceptable misrepresentation in online dating profiles. In recognition of the increasingly important role of social media in government and reflecting this year’s conference location, this year’s panel discussion addresses the topic of the role of Social Media in the US Government. The panel features Macon Phillips, the first White House Director of New Media, Haym Hirsh, the director of NSF’s Information and Intelligent Systems Division (which is sponsoring research in computational social media), and Don Burke of the CIA, who was instrumental in the development of the Intellipedia. This year, the papers are grouped into the following sessions: Influence and Composition in Social Networks, Dynamics and Diffusion in Welcome to the fourth meeting of the International Conference on Weblogs and Social Media! Research on social media sits at the intersection of several fields in the computer and social sciences; so, since their inception, ICWSM conferences have had an interdisciplinary flavor. This year, however, the conference has taken a leap forward in integrating research from multiple fields. As you read through the program, you will see that this is reflected not just in a balance in papers from several fields but also within the contributions themselves; many of the papers and posters demonstrate excellence in multiple areas. We think this increasing integration reflects a new level of maturity in the field — investigators have moved beyond simply applying their trusted methods to socialmedia topics, and have started to implement the ideas, approaches, and methods that are best suited to their research questions. We are optimistic that the marriage of approaches from the computer and social sciences that is represented at this year’s conference will contribute to continued synergistic collaborations among the increasing number of disciplines associated with research on social media. This integrative approach to understanding social media is exemplified in this year’s keynote talks and invited symposia. Robert Kraut’s keynote address, “Evidenced-based Design of Online Communities,” will focus on understanding what properties of online communities contribute to the success or failure of the community as a whole. Similarly, Michael Kearns’s keynote address, “Behavioral Experiments in Strategic Networks,” discusses humansubject experiments on strategic and economic interactions in social networks. Both talks combine theoretical ideas from diverse areas (sociology, computer-supported collaboration, economics and game theory) with experimental analysis of social interactions. The invited symposium, “Research on Social Media in the Social Sciences,” showcases research drawn from the fields of psychology, so- xv Social Networks, Microblogging, Analysis of Social Network Usage, and Sentiment and Language Analysis. The conference starts with a tutorial series. In keeping with the interdisciplinary balance of the conference, we have two tutorials this year covering relevant foundational material from the areas of social psychology and social network analysis. Cindy Chung and Jamie Pennebaker will provide an overview of text analytic methods for uncovering social and psychological signals in language. Marc Smith and Derek Hansen will review the fundamentals of social network analysis and their application to social media. Two additional tutorials introduce relevant technologies supporting social media analysis. John Breslin and Alexandre Passant will explore the opportunities offered by the integration of social and semantic web technologies. Jake Hofman will introduce the latest approaches for conducting social network analysis at scale with Hadoop. We are excited about this year’s lineup of tutorial presenters and look forward to the breadth of ideas they will share. ICWSM is committed to supporting the research community and encouraging research with shared, available data sets. This year’s data challenge has expanded on the 2009 ICWSM Spinn3r Blog Dataset with annotations and indexes from last year’s data challenge workshop, and is working to make yet more datasets available. A new dataset for 2010 is the ICWSM JDPA data contributed by J.D. Power and Associates. The dataset is a 330k-token corpus containing blog posts, product reviews, and press releases with detailed, manual annotation for mentions (named, nominal, pronominal), coreference, meronymy and sentiment (aggregate sentiment per entity, sentiment expressions with prior polarity, sentiment targeting relations, intensifiers, negators, neutralizers, committers). The corpus covers automotive and consumer electronics domains. The workshop takes place on the afternoon of the last day of the conference. More details about the data set and workshop are available in the frontmatter of this proceedings. Organizing a conference is a year-round commitment — from the conference committee, our AAAI colleagues and the program committee and reviewers. We also recognize, however, that it is only with the passion and commitment of those carrying out the research work and submitting papers, posters and demos that our meeting would take place at all, and so we reserve the greatest portion of our gratitude to everyone who made a submission. As our conference grows, so does the quality of submissions and the quality of the final accepted papers. This year we accepted 25 papers out of the 103 submitted. An additional 35 papers were accepted as 4-page posters. Of the 25 submitted poster papers, 19 were accepted. Both submitted demos were accepted. The organizers would like to thank the program committee for their hard work in selecting this set of papers. Even more importantly, we would like to thank the broader ICWSM community for the excellent technical work that was submitted. We are also grateful to Videolectures.net, which will once again provide video coverage of the full conference, including the tutorials, paper presentations and invited talks. xvi – William W. Cohen, Chris Diehl, Natalie Glance, Sam Gosling, Ashkay Java, Marti Hearst, Matthew Hurst, Nicolas Nicolov, & Ian Soboroff