Mar 30, 2009

Geographic distance of social ties

Barry Wellman published an interesting article on geographic distance of social ties. Below is from his publication webpage.  I'm all intrigued.  I'll be soon posting stories on the Flickr counterpart.

"Does Distance Still Matter in the Age of the Internet?" (Diana Mok, Juan-Antonio Carrasco and Barry Wellman, Urban Studies, 2009).  Our study is part of the broad debate about the role of distance and technology for interpersonal contact. To the best of our knowledge, this is the first study that systematically and explicitly compares the role of distance in social networks pre- and post-Internet. We analyze the effect of distance on the frequency of email, phone, face-to-face and overall contact in personal networks, and we compare the findings with its pre-Internet counterpart whose data were collected in 1978 in the same East York, Toronto locality. We use multilevel models with spline specification to examine the nonlinear effects of distance on the frequency of contact. We compare these effects for both very close and somewhat close ties, and for different role relationships: immediate kin, extended kin, friends and neighbours. The results show that email contact is generally insensitive to distance, but tends to increase for transoceanic relationships greater than 3,000 miles apart. Face-to-face contact remains strongly related to short distances (within five miles), while distance has little impact on how often people phone each other at the regional level (within 100 miles). The study concludes that email has only somewhat altered the way people maintain their relationships. The frequency of face-to-face contact among socially-close friends and relatives has hardly changed between the 1970s and the 2000s, although the frequency of phone contact has slightly increased. Moreover, the sensitivity of these relationships to distance has remained similar, despite the communication affordances of the Internet and low-cost telephony.

Mar 27, 2009

ACM Social Network Systems 2009 Workshop

Tao Stein (@Facebook) and I are organizing a wonderful workshop in Nuremberg next Tuesday. We will have 8 paper presentations and 2 invited talks on security -- all look very interesting.
ACM Social Network Systems 2009

Program
0900 - 1000: Security at a Large Social Network, Tao Stein (Facebook)
1000 - 1030: Botnets vs. Social Networks, Elie Bursztein (Stanford)
1030 - 1100: Break

1100 - 1230: Privacy and Security
Eight Friends Are Enough: Social Graph Approximation via Public Listings

Joseph Bonneau, Jonathan Anderson, Ross Anderson, Frank Stajano (University of Cambridge)
Anonymous Opinion Exchange over Untrusted Social Networks
Mouna Kacimi (Max Planck Institute for Informatics), Stefano Ortolani (Vrije Universiteit), Bruno Crispo (University of Trento)
PeerSoN: P2P Social Networking - Early Experiences and Insights
Sonja Buchegger, Doris Schiƶberg (TU Berlin, Deutsche Telekom Laboratories), Le Hung Vu (EPFL), Anwitaman Datta (NTU Singapore)
1230 - 1330: Lunch

1330 - 1500: The Ties that Bind
On the Strength of Weak Ties in Mobile Social Networks
Stratis Ioannidis, Augustin Chaintreau (Thomson)
Centralities: Capturing the Fuzzy Notion of Importance in Social Graphs
Erwan Le Merrer (INRIA), Gilles Tredan (University of Rennes 1)
Buzztraq: Predicting Geographical Access Patterns of Social Cascades using Social Networks
Nishanth Sastry, Eiko Yoneki, Jon Crowcroft (University of Cambridge)
1500 - 1530: Break

1530 - 1630: Personalizing Search
Towards Personalized Peer-to-Peer Top-K Processing
Xiao Bai, Marin Bertier (INSA de Rennes), Rachid Guerraoui (EPFL, Switzerland), Anne-Marie Kermarrec (INRIA Rennes, France)
Toward Personalized Query Expansion
Marin Bertier (INSA de Rennes, France), Rachid Guerraoui (EPFL, Switzerland), Anne-Marie Kermarrec, Vincent Leroy (INSA de Rennes, France)

Flash Floods and Ripples

My recent paper investigates the role of blogosphere as a social media. 
Flash Floods and Ripples: The Spread of Media Content through the Blogosphere. 
Meeyoung Cha, Juan Antonio Navarro Perez, and Hamed Haddadi
In Proc. of the AAAI Conference on Weblogs and Social Media (ICWSM) Data Challenge Workshop, San Jose, May 2009

We tracked down the occurrences of YouTube videos in blog posts and named the two key patterns we found: flash floods and ripples. Flash floods represent rapid cascade events, which we see in the spread of political videos. Ripples represent a slow propagation, which we see for old music videos. So just how rapid are flash floods? The graph below shows the time it took to propagate YouTube videos, based on their topics. News videos propagate by the hour and stop spreading after a week. Music videos continue to spread after several months.
Plot below shows the propagation pattern of one of the popular YouTube videos in the blogosphere. The video was an advertisement made by the Republican party for the U.S. Presidential Election, 2008. Like other news videos, it spread quickly in the network and was blogged about 79 times within a week!

Mar 26, 2009

Tag cloud on flickr research

Abstract of my recent submission on information propagation.

Wordle: paper abstract 2

ps: loving wordle!

Golden questions of the day

At systems seminar today, we had a discussion about this Eurosys 2009 paper: User Interactions in Social Networks and their Implications
Christo Wilson (UCSB), Bryce Boe (UCSB), Alessandra Sala (UCSB), Krishna Puttaswamy (UCSB), Ben Y. Zhao (UCSB)


Some thoughts and questions:

#1 Can we extract something useful from Facebook wall posts? Data mining? What do people talk about? See Google's flu paper (Nature).

#2 Why study user interactions at all? To look for invariant trends like Dunbar's number? Why is this important in systems research?

#3 There seems a clear distinction between "knowledge" and "interaction" when it comes to measuring tie strength, e.g., "I know him well, but haven't talked for a while". Knowledge part is not pronounced in OSNs. Can we infer tie strength or the level of trust without doing user studies?

#4 Why SybilGuard performs poorly in interaction graphs? It is not intuitive why SybilGuard should work better in interaction graph. In SybilGuard, information about social graph might be enough, because it only matters that you know the other friend is a real user, not a fake user. Fax-mixing properties SybilGuard exploits do not align well with a community structure that is embedded in OSNs.

#5 Links need to be tagged with a purpose. Simply knowing the social graph or the interaction graph may not be enough for many of the socially-enhanced applications.

#6 Low rate conversation made in OSNs could sum up to be quite valuable. See Google's flu paper.

#7 Need to be careful in drawing conclusions. Results could be extrapolated. Extra care needed in methodology.

#8 Related to "trust" in social ties.
Here is a link to the CHI2009 paper on measuring "tie strength" based on information available in online social networks (e.g., number of messages exchanged, word count, education level, mutual friends). Authors do surveys to get ground truth data and some of the survey questions are highly related to trust (e.g., would you lend this friend $100?).