Tag Archives: Recommender Systems

Controversial books: patenting the obvious?

Interesting NYTimes’s article (if you don’t want to register, use BugMeNot where you can find shared login and password pairs). Mikhail Gronas discovers that “reviewers gave more five-star reviews than two-star reviews, creating an upward sloping curve”. (…) “But the most telling variable is the one star rating. Professor Gronas found that books high on what he called the “controversiality index” are given almost as many one-star as five-star ratings, creating a horseshoe-shaped curve. As it turns out, these books also tend to have high sales.”
I’ve found these patterns analyzing Epinions.com ratings and trust statements (chech the graphs’ on the paper (pdf)) but actually I don’t think they are that surprising: they seem pretty obvious and I just reported them passing by.
What is really depressing is that Dartmouth is now in the process of patenting software that will be used to determine the “controversiality index”.
I’m happy that in Europe we are still fighting against a so-stupid-policy of being able to patent everything, no matter how trivial it is. In this case the controversiality level of a book is something like “if a book received as much 5 ratings as 1 and if the 5 and 1 ratings together are the vast majority of ratings and if the number of received ratings is over a threshold (probably depending on release time), then the book is controversial” (putting it in formula that produces a controversiality value would require 10 minutes at most).
By the way, I’m currently working on the concept of controversiality of users and hopefully a paper is on the way. Controversial users are users who are trusted by many and distrusted by many. (Bush is a good example, but this can happen to highly visible persons in general). The idea is that Local Trust Metrics make sense expecially for highly controversial users (for example, users who are trusted by more than 200 users and DIStrusted by more than 200 users in the community). For those users, it does not make sense to predict a trust value of 0.5 saying that you should trust this user as 0.5 but, instead, to predict you should trust this controversial user as 1 if, for example, all your friends trust her and 0 if all your friends distrust her.

Using social software for good: car pooling

Paul Resnick is researching on “ride sharing services that dynamically match riders with rides”. Read the very interesting and clear SocioTechnical Support for Ride Sharing scenario document. The idea is to make car pooling easier using ICT. If your interests contain trust, recommender systems and making the earth a better place, you should definitely read the paper. Maybe I’ll try to put up a project and submit to the local government, there was a car pooling project in Trento but it seems dead. Contact me if you are interested! [My impression is that often research does not produce useful and real benefit for society, this is a case in which we can put our brain activity for creating something useful and that can make a difference].
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CiteULike: A free online service to organize your academic papers

[I’ll write something about my trip in Israel later on, as time permits]
I just found on HubLog an online service I was really waiting for: CiteULike (a prototype service to manage your personal library of academic papers). When you are logged in and visiting a page related to a paper, you can post that paper to your online library using a bookmarklet. In doing so, you can also specify tags, a list of keywords you’d like to associate with this article (a la del.icio.us and flickr) and optional notes. The service is very similar to del.icio.us (simple, tag-powered and social), but precisely tailored for academic papers. You can also see all the papers tagged under a certain tag (for example networks). Cool!
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Travelling to Cyprus and Israel

I’m at Coopis 2004 right now (in Agia Napa, Cyprus) and next week I’ll move to Jerusalem in order to meet Zvi and other people of the Multiagent Systems Research Group of the Hebrew University of Jerusalem. I’ll be back in my office on November 9.
I was hoping to do a lot of work during the coopis conference but the wireless network is not working very well and so expect few or no blogging at all.
I almost forgot to say that I’m presenting “Trust-aware Collaborative Filtering for Recommender Systems” (find it under papers section). Check it out if you are interested in Recommender Systems and Trust.

Paper accepted for Coopis → looking for cheap place in Cyprus (through 2 degrees of separation)

Good news: my paper “Trust-aware Collaborative Filtering for Recommender Systems” got accepted for Coopis2004.
Bad news: the conference is hyper-expensive.
So I’m looking for hyper-cheap (possibly free) hospitality in Larnaca, Cyprus, from 25 Oct to 29 Oct 2004. I checked on couchsurfing (a site where people offers ospitality in their houses and a super-cool YASN [yes, you can express your friends list]) but I found none in Cyprus.
If we take for true the six degree of separation theorem, I should be connected to everyone in Cyprus by only six degrees of separation. So I guess there should be at least some cypriots in my friends of friends set, now i only need to find one of the connecting friends. So if you know someone in Cyprus, please become my friend and close the circuit (and don’t forget to write down the path from me to the cypriot host in the comments below). Thanks.


KnoBot [UPDATE: the link is often broken. the knobot page on Sourceforge is always up (thanks Zbigniew)]- An agent for decentralised knowledge exchange :KnoBot combines semantic web technology with a P2P design to build a trust based decentralised system for information selection and discovery.
I should check it better but looks a lot like what I want to do for my PhD.
On KnoBot news I found a similar and interesting project: the Matrix Public Network project.
Both ot the project have running code, so we can try them out.

Boycott the Daily Me!

From Boycott the Daily Me! by Sunstein:
“For democracy to work, people must be exposed to ideas they would not have chosen in advance. Democracy depends on unanticipated encounters. It is also important for diverse citizens to have common experiences, which provide a kind of social glue and help them to see they are engaged in a common endeavor. A world where people only read news they preselect creates a risk of social fragmentation.”
This is my greatest fear about Trust-aware Recommender Systems (or in general systems that personalize user experience): that people will be exposed only to what they already approuve and like.
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New personalized services

Erik comments on personalized services presented in these last couple weeks:
a9.com: (by Amazon) a personalized experience, though not quite personalized search).
Newsbot (also in Italian): (by Micro$oft) personalized news (with or without login).
Findory: personalized news (with or without login), but not new.
Google Personalized (weak attempt).
Interesting competition.

Cai Ziegler

During the past week I was in Oxford for the 2nd Trust Management Conference. The presentation (pdf) (sxi) of my paper went well.
Most of the participants were concerned with privacy and the problem of setting up a secure environment for virtual organizations (business basically). I am not too much interested in this topic that is basically agreeing with Microsoft, IBM and HP (that were present with some representatives) about standards for the trust management processes, often reduced to simple access control lists.

Instead I was very happy to meet Cai Ziegler. Cai is working on topics very similar to my interests. But it is doing more (his scope on semantic web recommender systems is broader, since he also takes into account taxonomies), better (its English is simply wonderful) and faster (he is still in his first year of PhD). Can I at least say I’m humble? ;-)
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