WWW 2013 22nd International World Wide Web Conference General Chairs: Daniel Schwabe (PUC-Rio – Brazil) Virgílio Almeida (UFMG – Brazil) Hartmut Glaser (CGI.br – Brazil) Research Track: Ricardo Baeza-Yates (Yahoo! Labs – Spain & Chile) Sue Moon (KAIST – South Korea) Practice and Experience Track: Alejandro Jaimes (Yahoo! Labs – Spain) Haixun Wang (MSR – China) Developers Track: Denny Vrandečić (Wikimedia – Germany) Marcus Fontoura (Google – USA) Demos Track: Bernadette F. Lóscio (UFPE – Brazil) Irwin King (CUHK – Hong Kong) W3C Track: Marie-Claire Forgue (W3C Training, USA) Workshops Track: Alberto Laender (UFMG – Brazil) Les Carr (U. of Southampton – UK) Posters Track: Erik Wilde (EMC – USA) Fernanda Lima (UNB – Brazil) Tutorials Track: Bebo White (SLAC – USA) Maria Luiza M. Campos (UFRJ – Brazil) Industry Track: Marden S. Neubert (UOL – Brazil) Proceedings and Metadata Chair: Altigran Soares da Silva (UFAM - Brazil) Local Arrangements Committee: Chair – Hartmut Glaser Executive Secretary – Vagner Diniz PCO Liaison – Adriana Góes, Caroline D’Avo, and Renato Costa Conference Organization Assistant – Selma Morais International Relations – Caroline Burle Technology Liaison – Reinaldo Ferraz UX Designer / Web Developer – Yasodara Córdova, Ariadne Mello Internet infrastructure - Marcelo Gardini, Felipe Agnelli Barbosa Administration– Ana Paula Conte, Maria de Lourdes Carvalho, Beatriz Iossi, Carla Christiny de Mello Legal Issues – Kelli Angelini Press Relations and Social Network – Everton T. Rodrigues, S2Publicom and EntreNós PCO – SKL Eventos e Turismo Student Volunteers Coordination: Wagner Meira (UFMG) Yasodara Córdova (NIC.br) Sebastien Forget (Canada) John Miller (Australia) (International Volunteers) Program Committee Behavioral analysis and personalization Eugene Agichtein (Emory U), Yoelle Mareek (Yahoo! Labs) – Chairs Members Mikhail Ageev, NIVC MGU Peter Bailey, MSR Nicolas Belkin, Rutgers University Paul Bennet, MSR Edward Bortnikov, Yahoo! Peter Brusilovsky Georg Buscher Nick Craswell, MSR Fernando Diaz, Microsoft Research Andy Edmonds Henry Feild, Umass Antonio Gulli Qi Guo, Emory University Jeff Huang Rosie Jones Diane Kelly, UNC Gueorgi Kossinets Dmitry Lagun, Emory University Mounia Lalmas Ronny Lempel, Yahoo! Labs Andreas Paepcke, Stanford Dan Pelleg Matt Richardson, MSR Kerry Rodden Tetsuya Sakai Mark Smucker, University of Waterloo Jaime Teevan Andrew Tomkins, Google Ingmar Weber Ryen White, MSR Yisong Yue Zijian Zheng, MSR Dav Zimak Program Committee - Content analysis Claire Cardie (Cornell), Evgeniy Gabrilovich (Google) – Chairs Members Aris Anagnostopoulos, University of Roma Donald Metzler Azin Ashkan, University of Waterloo Prasenjit Mitra, PSU Michael Bendersky, Umass Bo Pang Misha Bilenko, MSR Dmitry Pechyony, Technion Michael Cafarella, Umich Fuchun Peng, Yahoo! Yunbo Cao, MSR John Prager, IBM Carlos Castillo, U. of Chile Kunal Punera, Utexas Deepayan Chakrabarti, CMU Kira Radinsky Brian Davison, Lehigh U. Filip Radlinski, Microsoft Doug Downey, Northwestern U. Vibhor Rastogi Gideon Dror, Sunita Sarawagi, IIT Bombay Hui Fang, U. Del Burr Settles, CMU Dennis Fetterly, MSR Stefan Siersdorfer, University of Hannover Shantanu Godbole, Julia Stoyanovich, Upenn Iryna Gurevych Gerd Stumme, Uni, Kassel Bo, June Hsu, MSR Idan Szpektor, Yahoo! Tapas Kanungo Partha Talukdar Nick Koudas, U. of Toronto Xuanhui Wang, Yahoo! Georgia Koutrika, HP Gerhard Weikum Zornitsa Kozareva, USC, ISI Elad Yom, Tov Oren Kurland, Technion Torsten Zesch, Tu Darmstadt Lillian Lee, Cornell Hongyuan Zha, GATech Chengkai Li, UTA Chengxiang Zhai, UIUC Hao Ma, MSR Dell Zhang, BBK Qiaozhu Mei, Umich Program Committee - Software infrastructure and their performance, scalability, and availability Torsten Suel (PI), Zhi-Li Zhang (UMinnesota) – Chairs Members Michele Colajanni, University of Modena Pablo Rodriguez, Telefonica Research Anja Feldmann, TU Berlin Sambit Sahu, IBM Research Daniel Figueiredo, COPPE/UFRJ Subhabrata Sen, AT&T Research Krishna Kant, Intel Corporation Alexander Shraer, Google Purushottam Kulkarni, IIT Bombay Ramesh Sitaraman, Department of Computer Science, John C.S. Lui, The Chinese University of Hong Kong University of Massachusetts, Amherst Grzegorz Malewicz, Facebook Malgorzata Steinder, IBM Research Martin May, Technicolor Sandeep Uttamchandani, Beng Chin Ooi, National University of Singapore Jacobus Vandermerwe, Giovanni Pacifici, IBM Research Maja Vukovic, IBM Research Michael Rabinovich, Case Western Reserve University Zhen Xiao, Peking University Program Committee - Web mining Tanya Berger-Wolf (UIC), Bing Liu (UIC), Kyuseok Shim (SNU) – Chairs Members Charu Aggarwal, IBM Sangkeun Lee, Department of Computer Science and Amr Ahmed, Yahoo! Labs Engineering, Korea University Roberto Bayardo, Google Hang Li, Huawei Noah’s Arc Lab Smriti Bhagat, Technicolor Xiaoli Li, Institute for Infocomm Research Yun Chi, NEC Laboratories America Huan Liu, Arizona State University Chin, Wan Chung, KAIST Tie, Yan Liu, Microsoft Research Asia Gao Cong, Nanyang Technological University Yue Lu, University of Illinois at Urbana, Champaign David Crandall, Indiana University Michael Lyu Mayur Datar, Google Inc. Dunja Mladenic, J. Stefan Institute Eduard Dragut Bamshad Mobasher, DePaul University Georges Dupret, Yahoo! Labs Arjun Mukherjee, University of Illinois--Chicago Tina Eliassi, Rad, Rutgers University Olfa Nasraoui, University of Louisville Martin Ester, Department of Computer Science, Simon Zaiqing Nie, Microsoft Research Asia Fraser University, Canada Alexandros Ntoulas, Zynga Christos Faloutsos, Carnegie Mellon University Srinivasan Parthasarathy, Department of Computer Ronen Feldman, Hebrew University Science and Engineering, The Ohio State University Michael Gamon, Microsoft Research Jian Pei, Simon Fraser University C. Lee Giles, Pennsylvania State University Mark Sandler, Google Aristides Gionis, Aalto University Dou Shen, Microsoft Adcenter Labs Dimitrios Gunopulos, UoA Myra Spiliopoulou, U. Magdeburg Jiawei Han, University of Illinois at Urbana, Champaign Jaideep Srivastava, University of Minnesota Wook, Shin Han, Kyungpook National University Lei Tang, @WalmartLabs Shawndra Hill, University of Pennsylvania Masashi Toyoda, University of Tokyo Nitin Jindal, Google Jianyong Wang, Tsinghua University Jaewoo Kang, Korea University Ke Wang, Simon Fraser University U Kang, Carnegie Mellon University Michael Wurst, TU Dortmund Sang, Wook Kim, Hanyang University Hui Xiong, Rutgers University Irwin King, The Chinese University of Hong Kong Hwanjo Yu, POSTECH Mayank Lahiri, University of Illinois at Chicago Jeffery Xu Yu, Dept. of Systems Engineering & Wai Lam, The Chinese University of Hong Kong Engineering Mngt, Chinese University of Hong Kong Hady Lauw, Singapore Management University Philip Yu, UIC Dongwon Lee, Penn State University Lei Zhang, University of Illinois at Chicago Program Committee internet monetization and incentives Vanja Josifovski (Google), David Pennock (MSR NYC) – Chairs Members Ramakrishna Akella, School of Engineering University Benjamin Lubin, Harvard of California, Santa Cruz Vahab Mirrokni, Google Research Sugato Basu, Google Research S. Muthukrishnan, Rutgers University Ye Chen, Microsoft Uri Nadav Ingemar Cox, University College London Hamid Nazerzadeh, USC Marshall School of Business Nikhil Devanur, Microsoft Research Mallesh Pai, University of Pennsylvania Marcus Fontoura, Google Inc Sandeep Pandey, Twitter Arpita Ghosh, Cornell University Michael Schapira, Yale University & U.C. Berkeley Gagan Goel, Google Research James G. Shanahan, Independent Consultant (San Sreenivas Gollapudi, Microsoft Research Francisco) Ronen Gradwohl, Weizmann Institute of Science Jayavel Shanmugasundaram, Google Inc. Maria Grineva, Yandex Eric Sodomka, Brown University Ralf Herbrich, Facebook Jian, Tao Sun, Microsoft Research Asia Patrick Hummel Neel Sundaresan, eBay Research Labs Krishnamurthy Iyer, University of Pennsylvania Ankur Teredesai, University of Washington Shaili Jain, Yale University Siva Viswanathan, University of Maryland Patrick Jordan, Microsoft Haifeng Wang, Baidu Radu Jurca Jun Yan, Microsoft Research Asia Sebastien Lahaie M. Yenmez, Carnegie Mellon University Ying Li Georgios Zervas, Yale University Program Committee Search systems and applications Soumen Chakrabarti (IIT Mumbai), Wei-Ying Ma (MSR Asia) – Chairs Members Omar Alonso, Microsoft Chin Yew Lin, Microsoft Research Asia Jaime Arguello, University of North Carolina Ling Liu, Georgia Tech at Chapel Hill Tie Yan Liu, Microsoft Research Asia Ching Man Au Yeung, ASTRI Dmitri Loguinov, Texas A&M Shenghua Bao, IBM China Research Lab David Losada, University of Santiago de Compostela Behshad Behzadi, Google Inc. Massimo Melucci, University of Padua Gloria Bordogna, National Research Council Sung Hyon Myaeng, Kaist of Italy, CNR Jian Yun Nie, Universit de Montral Rui Cai, Microsoft Research, Asia Iadh Ounis, University of Glasgow Yi Chang, Yahoo! Labs Umut Ozertem, Microsoft Zheng Chen, Microsoft Research Asia Gabriella Pasi, Universit degli STudi di Milano Bicocca Hong Cheng, The Chinese University of Hong Kong Simone Paolo Ponzetto, University of Rome Tao Cheng, Microsoft Research Redmond Davood Rafiei, University of Alberta Xueqi Cheng, Institute of Computing Technology, Sriram Raghavan, IBM Research India CAS, P. R. China Stefan Rueger, Knowledge Media Institute Pablo De La Fuente, GRINBD. Universidad de Altigran S. Da Silva, Federal University of Amazonas Valladolid Ralf Schenkel, Saarland University Edleno Silva De Moura, Universidade Federal