Theory Tuesdays -- What do Wikipedia, car-pooling, couch surfing, and social bookmarking have in common?

Last fall, I worked for four months in Google, Zürich. It was a fun and enriching experience, indeed. The opportunity to learn and contribute to the technology that is used by millions of people daily is quite exciting.

Besides enjoying the Google-life, during my days in Zürich, I was invited by two artist friends, Silvan Käelin [1,2,3] and Philip Matesic [4,5,6]), to give a talk about my PhD thesis research at Perla Mode -- as part of the Theory Tuesdays project.

Philip organizes a weekly event at Perla Mode named Theory Tuesdays. The goal is to bring together artists, researchers (of multiple disciplines), and the public to discuss a variety of topics such as art, technology, society, and their intersection.

I received the invitation with surprise and interest. It was a new experience to talk to an audience completely outside my field of research. Also, it was a chance to receive feedback (from such non-technical group) about what I think it is a relevant topic of study.

The idea was to have a middle ground between what I have been investigating (i.e., techniques to assess the value of contributions in peer production systems [pdf]) and a the broader topic that could interest the attendance.

Therefore, it seemed appropriate to introduce the notion of peer production systems [7], hint the questions I am interested in answering in this context, and asking the participants related questions such as: how do they perceive the value of information they consume online? do they often perceive themselves contributing to others by producing information online? what is the main incentive to do so? What are the aspects they take into account to decided whether an information provider produces value to them?

I am glad that the "talk" turned into a lively conversation about about all these questions and other aspects related to online peer production. We covered topics from the basic notion of social production (and why it works so well in certain scenarios), passed through specifics about the utility of tagging (e.g., classification languages may emerge through collaboration), and talked about the intuition behind the techniques I am designing to assess the value of contributions in social tagging systems.

Although anecdotal, it was possible to observe from the discussion two explicit trends on the perception of value of online peer-produced information: novelty and trust on the information producer. These aspects came up in the discussions as crucial to the users to assess the value of peer-produced information. It is important to note that the information consumer's interest is an implicitly aspect considered in the value assessment.

The observations are somehow intuitive, but for me it was quite important and helpful to have a first-hand discussion with the real users of the systems I study. It does help one to tune the questions to ask and where the relevancy of one's research. I hope to have more opportunities like this. Thanks to Silvan and Philip for the first one.

References:

[1] One Man
[2] Lagoa do Ouro
[3] Temps de Poussiére (Time of Dust)
[4] An Bonus
[5] Mau Series
[6] To Don Pedro with Mr. Gonzalez
[7] Y. Benkler. "The Wealth of Networks: How Social Production Transforms Markets and Freedom"

Assessing the Value of Contributions in Tagging Systems

During the past two and a half months, I have been visiting the InWeb/UFMG at Belo Horizonte - MG - Brazil. Besides enjoying the great 'Cozinha Mineira', in this opportunity, we studied the problem of assessing the value of contributions in social tagging systems, and took the first steps towards a solution. The ideas will be presented in an article at the 2nd IEEE International Symposium on Social Intelligence and Networking (SIN-10) in 20-22August 2010. Next stop: to give a talk at the Laboratório de Sistemas Distribuídos (UFCG).

Abstract -- Assessing the value of individual users' contributions in peer-production systems is paramount to the design of mechanisms that support collaboration and improve users’ experience. For instance, to incentivize contributions, file-sharing systems based on the BitTorrent protocol equate value with volume of contributed content and use a prioritization mechanism to reward users who contribute more. This approach and similar techniques used in resource-sharing systems rely on the fact that the physical resources shared among users are easily quantifiable. In contrast, information-sharing systems, like social tagging systems, lack the notion of a physical resource unit (e.g., content size, bandwidth) that facilitates the task of evaluating user contributions. For this reason, the issue of estimating the value of user contributions in information sharing systems remains largely unexplored. This paper introduces this problem and takes the first steps towards a solution. More precisely, it presents a framework to design algorithms that estimate the value of user contributions in tagging systems, proposes three complementary success criteria for potential solutions, and outlines the methodological evaluation challenges.

Spam in social software

From the Greg Linden's blog:

An arms race in spamming social software
by Greg Linden (16 Oct 2009)
http://glinden.blogspot.com/2009/10/arms-race-in-spamming-social-software.html

The post presents an ultra-short, yet interesting, summary of spam strategies observed in social software. In particular, Greg Linden mentions several observed badmouthing strategies -- the spammer tries to taint competitors reputation, as opposed to attempt to use spam to obtain benefits directly. Interestingly, Chen and Friedman [1] conjecture that badmouthing attacks are harder to tackle than attacks that attempt to artificially boost one's reputation.

The post ends suggesting that incentive-based approaches to deter spam are (possibly good) alternatives compared to techniques that detect spam by focusing on content analysis (e.g., detection of commercial intent on blog comments). I would say they are complementary, though.

[1] Chen & Friedman. "Sybilproof Reputation Mechanisms".
http://doi.acm.org/10.1145/1080192.1080202

Relationship between cross-field citations and work impact

A recent work by Shi, Adamic , Tseng and Clarkson has an interesting analysis on the relationship between works that draw from different areas (i.e., cite papers outside their fields) and their subsequent impact. [1]

One of the interesting bits:

[...]
Intuitively, any individual citation will at most have a very weak impact on the success of a citing paper. It will only be one of possibly dozens of references made in an article or patent. Other factors, such as the publication venue and the reputation of the authors, are more likely to contribute to the impact of the article than any individual citation the authors include. We nevertheless see a significant relationship between the interdisciplinarity of citations and the impact of the publication.
[...]

This reminds me of previous results on the relationship between network constraint and value of ideas [2]. The intuition is that a person who is in a bridge position in her social network (i.e., connecting two distinct groups) is more exposed to different ways of thinking, which may lead to that person having more valuable ideas. Here, the social network is the citation network, and the bridges are papers that cite otherwise unconnected clusters (i.e., fields).

A recipe for higher impact research?

[1] Shi et al. 2009. The Impact of Boundary Spanning Scholarly Publications and Patents. PLoS ONE.
[2] Burt, R., 2003. Structural Holes and Good Ideas. American Journal of Sociology.

HPDC'2008 - Part I

Last week I participated to two great conferences: the International Symposium in High Performance Distributed Computing (HPDC) and the USENIX. Both events took place in Boston, MA, USA.

There a lot of interesting things to mention. Thus, to avoid a single long post, I will describe a few presentations that I attended (and discuss some ideas) in a series of short posts.

In the first two days at HPDC, there were two interesting workshops: UPGRADE-CN (P2P and Grids for the Development of Content Networks) and MMS (Managed Multicore Systems).

The two workshops had works related to the research projects I am currently working on.

Molina [1] presented his work on designing two protocols that enable collaborative content delivery in mobile transient networks. By transient networks, the authors mean networks composed of devices that are geographically co-located for a short period such as a music festival.

The authors suggest to exploit the multiple network interfaces currently available in most mobile devices and to enable collaborative use of these multihomed devices.

The idea is quite interesting. In particular, it raises some issues from the perspective of distributed resource sharing. It would be good to understand whether incentive mechanisms are necessary in transient networks. The idea is to encourage users to share their connections with a community for collaborative downloading/streaming of content.

On top of that, a nice follow-up work would be to investigate the feasibility of collaborative data dissemination protocols, which are widely used in the Internet (e.g. BitTorrent), in the transient networks scenarios.


[1] Molina et al. "A Social Framework for Content Distribution in Mobile Transient Networks". In UPGRADE-CN'2008.

"Yes, There Is a Correlation"

This week I came across an interesting paper: "Yes, There is a Correlation - From Social Networks to Personal Behavior on the Web" by Parag Singla (University of Washington) and Matthew Richardson (Microsoft Research) in WWW'2008.

In summary, they show that the similarity between the personal interests and attributes of two users who are MSN contacts is much higher than two random users. Moreover, I've found the problem formulation elegant and the scale of data non-trivial to handle (approx. 13 million unique users).


From the paper:

Summarizing the results, we showed that people who talk to each other on the messenger network are more likely to be similar than a random pair of users, where similarity is measured in terms of matching on attributes such as queries issued, query categories, age, zip and gender. Further, this similarity increases with increasing talk time. The similarities tend to decrease with increasing average time spent per message. Also, we showed that even within the same demographics, people who talk to each other are more likely to be similar. Finally, as we hop away in the messenger network, the similarity still exists, though it is reduced.

I wonder whether a similar level of correlation would be observed in online communities with other purposes, such as content-sharing (e.g. Flickr and YouTube).

Interesting Articles: IPTPS 2008

For those interested in the convergence of Online Social Networks and Peer-to-Peer Systems, it is worth taking a look at some articles in the program of the International workshop on Peer-To-Peer Systems (IPTPS).

Privacy is on the news!

These days, online privacy have attracted a great deal of attention in technology media [3][4]. Perhaps, the online privacy topic is an old concern in some specific conversation/technology/academic circles, but privacy control was apparently dragged to the general public attention more recently due to the surge of online social networks.

It was interesting to see that online service providers as Ask.com is try to sell privacy control as one feature that differentiates them from their competitors [1].

Although there is an interest in the market to raise some awareness about privacy and to allow users to control the access to their online footprints [2], there is a question whether this will attract more consumers or not.

Regardless, I think the user must have the option of fine tunning the disclosure of his/her explicit and implicit online "footprints". Moreover, I believe that certain domains could benefit from systems designed around the high-level concept of online social networking, if better privacy control capabilities are put in place.


References

[1] Ask Eraser. http://sp.ask.com/en/docs/about/askeraser.shtml
[2] Attention Trust. http://www.attentiontrust.org.
[3] Will Privacy Sell?. Slashdot.org. December, 11, 2007.
[4] Evolving Privacy Concerns. MIT Technology Review. December, 11, 2007.

Digital Libraries and User Attention


This past week, I attended to the JCDL'2007 (Joint Conference in Digital Libraries) and the CAMA'2007 (International ACM/IEEE Workshop on Contextualized Attention Metadata).

Since I cannot comment every single interesting paper that I've seen and discussed about (there are so many), I will point two interesting papers:

The first, which was also the very first presentation of the conference, World Explorer: Visualizing Aggregate Data from Unstructured Text in Geo-Referenced Collections (presented by Rahul Nair). This is a cool tool built on top of Flickr geotagging features. It is really nice to see how many applications are possible considering on-line communities like Flickr and del.icio.us that incorporate tagging features.

The main opportunity explored by the authors is to use geo-reference to cluster content. Besides a simply photo sharing mechanism, I think geotagging also opens up several research challenges/opportunities on designing applications for urban sensing.

The second paper was Can Social Bookmarking Enhance Search in the Web? (presented by Y. Yanbe).

The authors propose the introduction of what I would call a "Ranking Aggreagator" mechanism between the user, Google PageRank and del.icio.us ranking. Thus, their observation is that extremely fresh web pages tend to get low PageRank, but they may have a fair number of bookmark occurrences in del.icio.us. Therefore, they propose a combination of both ranking schemes to improve the ranking of fresh pages and allow the user to get good mix of 'reputable' pages via PageRank and popular pages on del.icio.us. Actually, I wondered if a combination of Google search history and the user interest sharing could be combined to provide better personalized search results.

I also participated to an interesting workshop, CAMA'2007, organized by Erik Duval, Martin Wolpers and Jehad Najjar.

The first talk by Seth Goldstein was exciting, possibly because it shows the incredibly large number of business opportunities are orbiting on-line social networks and how much value there is on online users attention

Joe Pagano from the Library of Congress presented some results on measuring the audience of a newly launched web site. His main finding was that more visitors come from blogs than from search engines, just to reinforce the intuition on the blog influence on the information consumption in the Web.

Personally, a positive aspect of this workshop was to identify possible applications that may validate our preliminary studies on interest sharing in collaborative tagging communities. For example, an extension on Joe Pagano's work would be the application of our interest sharing graph to understand how these visitors relate to each other and whether they from sub-communities of interest.

Also, Erik Duval made a nice comment on the fact that the large number of unique users we have found in our investigation over CiteULike and Bibsonomy may still present rich information to recommendation systems, even though these users are not connected to any island of interest we depicted in the interest sharing graph (more details here).

This is a brief summary of what I have seen this past week. Now, a lot of ideas to refine and put in practice...