Tag Archives: Research

MIT Press book “The Reputation Society” (containing a chapter by me) is out!

The MIT Press I contributed to with a chapter is out! It is titled “The Reputation Society: how online opinions are reshaping the offline world” and edited by Hassan Masum and Mark Tovey.
It is available on MIT press and on Amazon.
The chapter I wrote is titled Trust It Forward: Tyranny of the Majority or Echo Chambers? and on it I ramble about objectivity/subjectivity, minorities/majorities, etc.

If reputation systems weight all perspectives similarly, they may devolve into simple majority rule. But if they give each user reputation scores that take only other similar users’ opinions into account, they run the risk of becoming “echo chambers” in which like-minded people reinforce each others’ views without being open to outside perspectives. Massa discusses design choices and trust metrics that may help balance these two extremes and the broader implication for our future societies.

the reputation society book cover The book received endorsements by people I really admire.
“As our societies expand from local villages to global networks, our ways of assessing and sharing reputation—the foundation of trust and community—must also evolve, but how? The thoughtful and thought-provoking essays in The Reputation Society bring a wide range of perspectives to this question, including the design of technological solutions, applications in philanthropy, science and governance, and warnings about the loss of privacy and autonomy. It is a fascinating collection of readings not only for scholars, but for anyone interested in the dynamics of the reviews and recommendations that shape our decisions—or in the future of how we will judge and be judged.”
Judith Donath, Fellow, Berkman Center for Internet and Society, Harvard University

“Today is tomorrow’s yesterday. These provocative essays, by some of the leading thinkers in the domain of reputation systems, illuminate how reputations regulate actions across time and social distance and point to the opportunities and obstacles that reputation systems present for commerce and democracy.”
Paul Resnick, Professor, University of Michigan School of Information

“The Reputation Society enriches the discussion of reputation by bringing together technologists, philosophers, legal scholars, and industry leaders to sort through the promise and perils we face today. It covers the practical, for those interested in the nuts and bolts of the challenges we face today, and the theoretical, for those looking to engage in broader discussions of the ethical and moral concerns. In short, a terrific and enlightening read!”
Danielle Keats Citron, Professor of Law, University of Maryland School of Law

The list of my co-authors is also very delightful.
Trust, reputation systems, and the immune system of democracy / Craig Newmark
Building the reputation society / Hassan Masum, Mark Tovey, & Yi-Cheng Zhang
Designing reputation systems for the social web / Chrysanthos Dellarocas
Web reputation systems and the real world / Randy Farmer
An inquiry into effective reputation and rating systems / John Henry Clippinger
The biology of reputation / John Whitfield
Regulating reputation / Eric Goldman
Less regulation, more reputation / Lior Strahilevitz
The role of reputation systems in managing online communities / Cliff Lampe
Attention philanthropy : giving reputation a boost / Alex Steffen
Making use of reputation systems in philanthropy / Marc Maxson & Mari Kuraishi
The measurement and mismeasurement of science / Michael Nielsen
Usage-based reputation metrics in science / Victor Henning, Jason Hoyt, and Jan Reichelt
Open access and academic reputation / John Willinsky
Reputation-based governance and making states “legible” to their citizens / Lucio Picci
Trust it forward : tyranny of the majority or echo chambers? / Paolo Massa
Rating in large-scale argumentation systems / Luca Iandoli, Josh Introne, & Mark Klein
Privacy, context, and oversharing : reputational challenges in a Web 2.0 world / Michael Zimmer & Anthony Hoffman
The future of reputation networks / Jamais Cascio
“I hope you know this is going on your permanent record” / Madeline Ashby & Cory Doctorow.

The cover of the book reads as follows.

In making decisions, we often seek advice. Online, we check Amazon recommendations, eBay vendors’ histories, TripAdvisor ratings, and even our elected representatives’ voting records. These online reputation systems serve as filters for information overload. In this book, experts discuss the benefits and risks of such online tools.

The contributors offer expert perspectives that range from philanthropy and open access to science and law, addressing reputation systems in theory and practice. Properly designed reputation systems, they argue, have the potential to create a “reputation society,” reshaping society for the better by promoting accountability through the mediated judgments of billions of people. Effective design can also steer systems away from the pitfalls of online opinion sharing by motivating truth-telling, protecting personal privacy, and discouraging digital vigilantism.

Paper “Wikipedia research and tools: Review and comments”

The draft paper “Wikipedia research and tools: Review and comments” by Finn Arup Nielsen (dated March 17, 2011) is a very useful 56-pages resource highlighting key areas of research for Wikipedia (with citations to relevant work already published). The key areas identified are in the following. The cited papers (with annotations!) are 236! Even if this is draft paper, it is a super valuable resource! Check the pdf file.

Identified key research areas. Quality, Factual errors, Coverage and bias, Actuality, Sources, Accessibility, Size across languages, Network analysis, matrix factorizations and other operations, Genre, Article feedback, Vandalism reversion, Biased editing, Use of Wikipedia in court, User contributions, User characteristics, Organization, Popularity, Why do people edit?, Why do people leave?, Why does it work?, Serving content, Using categories, Thesaurus construction, Translation, Trend spotting and prediction, Searching with Wikipedia, Databasing the structured content, Geography, Extending Wikipedia, Quality assessment, certification and rating, Automatic creation of content, Tables and databases, Semantic wikis, Form-based editing, Markup, Extended Authoring, Geographical extension, Extending browsing, Graphic extensions, Video extensions, Real-time editing, Distributed and disconnected Wikipedia, Wiki and programming, Using Wikipedia and other wikis in research and education, Attitude towards Wikipedia, Use of Wikipedia, Citing Wikipedia, Special wikis, Censorship, Carl Hewitt vs. Wikipedia, Wikipedia and wikis as a teach- project, Wikiversity, serves the purpose of building a ressource for teaching and learning tool, Using wikis for course communication, Textbooks, Future.

Abstract: I here give an overview of Wikipedia and wiki research and tools. Well over 1,000 reports have been published in the field and there exist dedicated scientific meetings for Wikipedia research. It is not possible to give a complete review of all material published. This overview serves to describe some key areas of research.

Credits: Image by XKCD released under a Creative Commons Attribution-NonCommercial 2.5 License.

Papers about Wikipedia at CSCW 2010

February report of few papers about Wikipedia at CSCW conference by David Karger at Haystack Blog, MIT CSAIL Research.
The paper briefly reviewed are
* Socialization Tactics in Wikipedia and their Effects, by Choi, Alexander, Kraut and Levine: studied how participants early experiences of Wikipedia—whether they were invited or began editing on their own; whether their work was ignored, admired, or critiqued; what kind of advice they received—affected users later participation in and contributions to Wikipedia.
* The work of sustaining order in Wikipedia: The banning of a vandal by Geiger and Ribes
* Readers are Not Free-Riders: Reading as a Form of Participation on Wikipedia, by Antin and Cheshire: the more you know about wikipedia (sampled with a survey), the more you participate
* Egalitarians at the Gate: One-Sided Gatekeeping Practices in Participatory Social Media, by Keegan and Gergle: which breaking news stories are featured on the front page? They studied whether this decision is made in an egalitarian fashion or whether some individuals have significantly more power. Most interestingly, they found that certain ‘elite users’ who participate in the discussion to an unusually high degree do have inordinate power to “spike” stories, preventing them from appearing, but do not seem to have power to push stories they like into appearance.
* Beyond Wikipedia: Coordination and Conflict in Online Production Groups by Kittur and Kraut. Interestingly they studied Wikia.com, a service hosting over 6000 distinct wikis all running on the same Mediawiki platform as Wikipedia. The uniformity of implementation meant that it could be ruled out as a source of different behaviors in different wikis.

Review of “Feedback Effects between Similarity and Social Influence in Online Communities”

Today I presented to the other SoNetters a wonderful paper titled “Feedback Effects between Similarity and Social Influence in Online Communities” by David Crandall, Dan Cosley, Daniel Huttenlocher, Jon Kleinberg, Siddharth Suri of Cornell University, presented at the 2008 KDD conference on Knowledge discovery and data mining. My review just under the slides I used for the presentation.

Besides the points already presented in the slides, here I add few points relevant for our research on Wikipedia.

Social influence: People become similar to those they interact with
Interaction ? similarity
Selection: People seek out similar people to interact with
Similarity ? interaction

They considered registered users to the English Wikipedia who have a user discussion page (~510,000 users as of April 2, 2007). They are responsible for 61% of edits to the roughly 3.4 million articles. They ignore actions by users without discussion pages, who tend to have very few social connections.

User’s activity vector v(t): number of times that he or she has edited each article up to that point in time t.
Similarity(u,v): similarity between activity vectors of user u and v.
Time of ?rst meeting for two users u and v = time at which one of them ?rst makes a post on the user discussion page of the other.

In principle, we could also try to infer social interactions based on posting to the interactions based on posting to the same article’s discussion page. Moreover, we found that using simple heuristics to infer interaction based on posts to article discussion pages produced closely analogous results to what we obtain from analyzing user discussion pages.

They ?nd that there is a sharp increase in the similarity between two editors just before they ?rst interact (selection), with a continuing but slower increase that persists long after this ?rst interaction (social influence).

They also create a model and estimate the unobservable parameters based on maximum-likelihood. The estimates are as follows:
* The parameter ?, the probability of communicating versus editing, was 0.058 (i.e. every 100 actions, 6 are talks while 94 are page edits). We can cite it and we can even verify this across different wikipedias and at different time slots.
* When considering article edits as actions, the article is chosen from one’s own interests with probability ? = 0.35, from a neighbor’s interests with probability ? = 0.081, from the overall interests of Wikipedia editors with probability ? = 0.5, and by creating a totally new article with probability ? = 0.069.
* When considering talks as actions, the user to communicate with is chosen randomly from the overall set of users with probability ? = 0.71, and someone who has engaged in a common activity with probability 1-? = 0.29

They also do some content analysis (30 instances of two users meeting for the ?rst time. We examined the content of the initial communication and any reply, looking for references to speci?c articles or other artifacts in Wikipedia. We also compared the edit history of the two users).
Of the 30 messages, 26 referenced a speci?c article, image, or topic. In 21 cases, the users had both recently worked on the artifact that was the subject of conversation.
The gap between co-activity and communication was usually short, often less than a day, though it stretched back three months in one case.
Informally, communications tended to fall into a few broad categories: o?ering thanks and praise, making requests for help, or trying to understand the editing.behavior of the other person.
This sample of interactions suggests that people most often come to talk to each other in Wikipedia when they become aware of the other person through recent shared activity around an artifact. Awareness then leads to communication, and often coordination.

A really wonderful paper!

Two talks by David Orban in Trento on April 8th: The Open Internet Of Things, and

The SoNet FBK research group is happy to invite you to two talks by David Orban on April 8th in Trento.
The first talk, “The Open Internet Of Things”, will be about OpenSpime. It will be interesting if you are interested in sensors, positioning devices and memory, social, Web 2.0-style services in the real world, green technology, tech applied to the environment, open hardware and software, communications protocols, and future in general.
The second talk, “Preparing Humanity For The Impact Of Accelerating Technological Change”, will talk about the Singularity University, a recent new initiative funded by Nasa, Google and more.
I’ll wait you on April 8th!

First talk: The Open Internet Of Things
8 April 2009 – at 10.00 – Conference Room – Fondazione Bruno Kessler – Povo (TN) (up in the hills, see the map)
If we want the the forthcoming Internet of Things to flourish, the distributed smart sensor networks which take the current infrastructures for granted and base their necessarily autonomous activities on massive data collection, then we have to adopt an open architecture. Only an interoperable approach to the design of the next generation of hardware and software systems is going to be able and leverage the dramatic effects, and express the value to human civilization that the network of tens, or thousands of billions of new objects, the spime network is going to shape. For more info see http://www.openspime.com

Second talk: Preparing Humanity For The Impact Of Accelerating Technological Change
8 April 2009 – at 15.00 – Conference Room – Fondazione Bruno Kessler – Trento (downtown, see the map)
The impact of advanced technologies on our societies is becoming more and more extreme, exposing new tensions in our models of human relationships, learning, and values in policies, politics, and business. While relinquishment has been recommended by some, it appears that the way ahead will be the use of more, not less technology, as billions of people aim to achieve a high quality of life for themselves, and their children. The Singularity University, recently formed on an open, international and interdisciplinary approach employs an advanced curriculum to analyze how the future leaders of enterprise, culture, and science can best prepare to face the serious challenges ahead.

About the speaker:
David Orban is an entrepreneur and visionary. In recognition of his lifetime contribution to exponentially advancing technologies, he has been honored with the position of Advisor and European Lead to the prestigious Singularity University.
He is a Founder and Chief Evangelist of WideTag, Inc., a high technology start-up company providing the infrastructure for an open Internet of Things. David cuts across the limits of deep specialization to contribute to the new renaissance. He explains, “My vision is at the crossroads of technology and society as defined by their co-evolution.” David Orban’s personal motto is, “What is the question I should be asking?” This concept is his vehicle to accelerating cycles of invention and innovation in order to build the new world ahead.

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Insights into relationships on Facebook

Interesting blog post by Cameron Marlow, research scientist at Facebook over at overstated.net: Maintained Relationships on Facebook.

They start from a simple question: is Facebook increasing the size of people’s personal networks?

They looked at the communications of a random sample of users over the course of 30 days and defined networks in 4 different ways:

  • All Friends: the largest representation of a person’s network is the set of all people they have verified as friends. In research papers this number ranges between 300 and 3000. In facebook on average every users has 120 friends.
  • Reciprocal Communication: as a measure of a sort of core network, we counted the number of people with whom a person had had reciprocal communications, or an active exchange of information between two parties. In research papers, this numbers ranges from 3 as individuals with whom I can discuss important matters (for Americans) to 10 or 20 as ongoing contacts at a university.
  • One-way Communication: the total set of people with whom a person has communicated.
  • Maintained Relationships: the set of people for whom a user had clicked on a News Feed story or visited their profile more than twice. This is a sort of over-the-shoulder relationship, I’m “following” (this is the relationship type) the target user without she necessarily knowing it. This is a new type of relationship (not really available says 50 years ago), similar to reading the flow of thoughts of someone via a blog or just looking at the pictures uploaded on Flickr.

An interesting observation: “as a function of the people a Facebook user actively communicate with, you are passively engaging with between 2 and 2.5 times more people in their network”.

And another one: The stark contrast between reciprocal and passive networks shows the effect of technologies such as News Feed. If these people were required to talk on the phone to each other, we might see something like the reciprocal network, where everyone is connected to a small number of individuals. Moving to an environment where everyone is passively engaged with each other, some event, such as a new baby or engagement can propagate very quickly through this highly connected network.

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Social Networks and Web 2.0 papers at WWW2009

The recently announced list of accepted papers at WWW 2009 conference is at the end of this post. I’m particularly interested in the track “Social Networks and Web 2.0” and in the following papers:

  • Ulrik Brandes, Patrick Kenis, Juergen Lerner and Denise van Raaij. Network Analysis of Collaboration Structure in Wikipedia
  • Yutaka Matsuo and Hikaru Yamamoto. Community Gravity: Measuring Bidirectional Effects by Trust and Rating on Online (mentioning the Epinions dataset, maybe the dataset I released on Trustlet)
  • Shilad Sen, Jesse Vig and John Riedl. Tagommenders: Connecting Users to Items through Tags
  • Jérôme Kunegis, Andreas Lommatzsch and Christian Bauckhage. The Slashdot Zoo: Mining a Social Network with Negative Edges
  • Cristian Danescu Niculescu-Mizil, Gueorgi Kossinets, Jon Kleinberg and Lillian Lee. How opinions are received by online communities: A case study on Amazon.com helpfulness votes
  • Meeyoung Cha, Alan Mislove and Krishna Gummadi. A Measurement-driven Analysis of Information Propagation in the Flickr Social Network

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My chapter in “Computing with Social Trust”

Computing with Social TrustThe book “Computing with Social Trust” is out. In it you can find a chapter by Paolo Avesani and myself about my PhD work on Trust in Recommender Systems. You can download my chapter or buy the dead-tree book from Amazon. Following you can find the Table of contents. Enjoy!


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Happiness as a contagious virus: please spread it!

Some papers are more worth than others.
Dynamic spread of happiness in a large social network: longitudinal analysis over 20 years in the Framingham Heart Study by James H Fowler and Nicholas A Christakis.
Solid analysis based on data from 4739 individuals followed from 1983 to 2003.

Conclusions People’s happiness depends on the happiness of others with whom they are connected. This provides further justification for seeing happiness, like health, as a collective phenomenon.

Objectives To evaluate whether happiness can spread from person to person and whether niches of happiness form within social networks.

Clusters of happy and unhappy people are visible in the network, and the relationship between people’s happiness extends up to three degrees of separation (for example, to the friends of one’s friends’ friends).
People who are surrounded by many happy people and those who are central in the network are more likely to become happy in the future.
Longitudinal statistical models suggest that clusters of happiness result from the spread of happiness and not just a tendency for people to associate with similar individuals. A friend who lives within a mile (about 1.6 km) and who becomes happy increases the probability that a person is happy by 25% (95% confidence interval 1% to 57%). Similar effects are seen in coresident spouses (8%, 0.2% to 16%), siblings who live within a mile (14%, 1% to 28%), and next door neighbours (34%, 7% to 70%). Effects are not seen between coworkers. The effect decays with time and with geographical separation.

(credits: Photo by beija-flor released on Flickr under Creative Commons Attribution Noncommercial No Derivative license)

Kickoff meeting and public presentation for LiveMemories project with Ricardo Baeza-Yates from Yahoo! Research

livememories Wednesday October 22th 2008, in Trento there will be the kickoff meeting for the LiveMemories project, Active Digital Memories of Collective Life (in which I’m involved). The public workshop is open to everybody (it will be at least translated in Italian).
UPDATE: Now with blog in Italian http://lamemoriaaltempodiinternet.wordpress.com.
Check the program of the workshop or read it here below copy and pasted. There will be Ricardo Baeza-Yates, Director of the Yahoo! Research labs at Barcelona speaking about the Impact of Social Networks, Alessandro Cavalli – Professore di Sociologia, Università di Pavia, speaking about “La Costruzione Sociale della Memoria Collettiva”, Simon Delafond – Web producer – BBC, UK speaking about “BBC Memoryshare initiative” and presentations from the project partners and a collective discussion about “Quale modello per la libera circolazione della Memoria?”

I’m really looking forward for the event! If you are interested or you are coming, please let me know! See you!

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