Wisdom of Crowds or Wisdom of a Few?
- Ricardo Baeza-Yates Yahoo Labs, USA
In this keynote we give an introduction to wisdom of crowds in the Web, the long tail of web content, and the bias involved in the generation of user generated content (UGC). This bias creates the wisdom of ad hoc crowds or the wisdom of a few. Although it is well known that user activity in most settings follows a power law, that is, few people do a lot, while most do nothing, there are few studies that characterize well this activity. In a recent analysis of social network data we corroborated that a small percentage of the active users (passive users are the majority) represent at least the 50% of the UGC. As a sub-product, we also found a lower bound for the digital desert, the content in the Web that nobody reads. These results implies that most of the wisdom comes from a few users, which is not that surprising, as the Web is a reflection of our own society, where economical or political power also is in the hands of minorities.
Ricardo Baeza-Yates is VP of Research for Yahoo Labs leading teams in United States,
Europe and Latin America since 2006 and based in Sunnyvale, California, since August 2014.
During this time he has lead the labs in Barcelona and Santiago de Chile. Between 2008
and 2012 he also oversaw the Haifa lab. He is also part time Professor at the Dept. of
Information and Communication Technologies of the Universitat Pompeu Fabra,
in Barcelona, Spain. During 2005 he was an ICREA research professor at the same
university. Until 2004 he was Professor and before founder and Director of the
Center for Web Research at the Dept. of Computing Science of the University of Chile
(in leave of absence until today). He obtained a Ph.D. in CS from the University of
Waterloo, Canada, in 1989. Before he obtained two masters (M.Sc. CS & M.Eng. EE) and
the electronics engineer degree from the University of Chile in Santiago.
He is co-author of the best-seller Modern Information Retrieval textbook,
published in 1999 by Addison-Wesley with a second enlarged edition in 2011,
that won the ASIST 2012 Book of the Year award. He is also co-author of the
2nd edition of the Handbook of Algorithms and Data Structures, Addison-Wesley,
1991; and co-editor of Information Retrieval: Algorithms and Data Structures,
Prentice-Hall, 1992, among more than 500 other publications. From 2002 to 2004
he was elected to the board of governors of the IEEE Computer Society and in
2012 he was elected for the ACM Council. He has received the Organization of
American States award for young researchers in exact sciences (1993), the Graham Medal
for innovation in computing given by the University of Waterloo to distinguished
ex-alumni (2007), the CLEI Latin American distinction for contributions to CS in
the region (2009), and the National Award of the Chilean Association of Engineers (2010),
among other distinctions. In 2003 he was the first computer scientist to be elected
to the Chilean Academy of Sciences and since 2010 is a founding member of the Chilean
Academy of Engineering. In 2009 he was named ACM Fellow and in 2011 IEEE Fellow.
Communities and privacy in mobile phone social networks
- Vincent Blondel Université catholique de Louvain, Belgium
We describe several recent results on large network analysis with a special emphasis on community detection and on the analysis of mobile phone datasets. In particular, we describe the Louvain method that and can be routinely used for analyzing networks with billions of nodes or links. We analyze communities obtained on a nationwide dataset of criminal records, as well as on a social network constructed from mobile phone communications that span periods covering several months. We also describe applications of mobile phone dataset analysis for a range of applications such as urban planning, traffic optimization, monitoring of development policy, crisis management, and control of epidemics. With these applications in mind we overview results obtained in the ''Data for Development'' (D4D) challenge on the analysis of mobile phone datasets. We analyze the privacy threats of anonymized mobile phone dataset and show that human behavior puts fundamental natural constraints to the privacy of individuals.
Vincent D. Blondel is professor of applied mathematics and president of the University of Louvain (Belgium). He is affiliated with the Massachusetts Institute of Technology (Cambridge, USA) where he was a visiting professor and Fulbright scholar. He has held various appointments, including at Oxford University, at the Royal Institute of Technology (Stockholm, Sweden), at INRIA (Paris), and at the University of California (Santa Barbara). Vincent has directed more than thirty PhD and Master thesis. He is an IEEE Fellow and is the recipient of several international prizes, including the IEEE Ruberti prize and the SIAM prize on control and systems theory. He is a pioneer in the analysis of mobile phone datasets and the organizer of several international challenges on mobile phone datasets analysis. His recent work has been widely featured, including in Wired, Technology Review, Le Monde, La Recherche, BBC, CNN, Der Spiegel, The Wall Street Journal and The New York Times.
- Sinan Aral MIT Sloan School of Management, USA
- Noshir Contractor Northwestern University, Dept. of Industrial Engineering & Management Sciences, USA
- Jaideep Srivastava University of Minnesota, USA and Qatar Foundation, Qatar