Paolo blog: Ramblings on Web2.0, Trust, Reputation, Recommender Systems, Social Software, Free Software, ICT4D and much more

One of my interest is “How can information technology improve lives in the developing world?” (sentence from this post). If you are interested in this topic, you will enjoy Ethan Zuckerman’s ramblings on Africa, technology and media and particularly the post titled Mike Best with evidence that ICT4D works….
[I don’t like the term “developing world. In Italian I tend to use “paesi del Sud del Mondo”, that it is not 100% satisfactory as well since you could argue that Sud (south) can be intended as less valuable than North but I don’t agree: on many topics, the word South can carry more positive values than the word North]

While I think PageRank is a very clever (though simple) idea, I’m not very sure about HITS. What this algorithms are for? For predicting the quality of a page on the Web based on all the links between pages. PageRank assumes that a page linked by many pages and linked by pages of high quality (recursive!) has a good quality, i.e. it is an authority. HITS is based on the notions of hub and authority: a good hub is a page that points to several good authorities; a good authority is a page that is pointed at by several good hubs.
So, why do I appreciate PageRank and less HITS? Because the latter can be easily attacked. The PageRank of this page depends only on the pages linking to this page and I cannot easily force everyone on the web to link to this page. It depends on what other pages decide to link and I have no power over it.
Conversely, according to HITS, the hubness of this page depend on the pages this page link to, and I have total power over the pages I link to! Do I want this page to become an hub about cars? It is enough to link to (what I think are) cars authorities: bmw, mercedes, ferrari, ford, renault, … (fiat is better not). Then do I want to exploit the hubness score this page got? I would simply link also to crappyCarsISell.com. HITS thinks this page is an hub and, since an hub by definition points to authorities, hence HITS thinks crappyCarsISell.com is a car authority.
What matters is Direction of links! I have no control on links that go in my page but I have total control in links that go out of my page. Anyway I think the work by Kleinberg is simply great but HITS does not take into account the fact that users will always try to game systems (especially, but not only, if they have an immediate benefit).
… I was almost forgotting the initial reason of this post: I got remind about HITS reading Lexical authorities in an encyclopedic corpus: a case study with Wikipedia by my friend Francesco, whose blog I just discovered today via a comment he left here. And this means one less friend without a blog! Welcome Francesco!

Graphs, Networks, PowerLaws, Relationships and everything you like.
Network analysis of the Flickr population, based on data collected on January 8th, 2005, and some additional analyses. There is also a March 2005 version.

USA is used to release a report on Human Rights for every country in the world. Every country but the USA. So China thought about filling the gap and presented The Human Rights Record of the United States in 2004. (i read the comment in Italian by Repubblica). Interesting reading, full of data, numbers and stats. This is a link to Yahoo Cache version, just in case.
Of course nobody could argue that China is better than USA about Human Rights. But it is interesting that China is explicitly attacking USA on such a topic: can you imagine any other country releasing such a report? By the Information Office of the State Council of the People’s Republic of China. I can’t. With this report, China is saying “we are as powerful as you and we can judge you, as you judge all the world”. This is a scary situation for our future.
Continue Reading

GUESS: The Graph Exploration System by IBM seems a very interesting tool if you have fun managing and playing with graphs but I didn’t have time to try it yet. They say Source code available soon, if you have some desperate need for it in the meantime just email me and GUESS uses some great open source software including Piccolo, JUNG, HSQLDB, Jython , and RServe. I use JUNG and it is a delicious piece of software. If GUESS is able to improuve it and to give something more, it is probably an astonishing piece of software (and it is open source)

Article over at The Economist United we find on Collaborative Filtering. It is interesting to note that it speculates also on attacks to Recommender Systems. An interesting (simple as it should be) idea is the following:
Nolan Miller, of Harvard University’s Kennedy School of Government, and his colleagues (…) probabilistic techniques to determine whether a score is likely to be �honest�, by spotting unusual-looking patterns in scoring. Dozens of accounts created on the same day, all of which give high scores both to a bestseller and a new book, for example, might be an orchestrated attempt by a publisher to get fans of the former to buy the latter.
Continue Reading

I don’t agree with Lucas when he reasons about the Limitations of Google OS. He says In any computing application where there is a sense of responsibility, the computer must be owned by the person or organization who owns the responsibility. A desktop company like Microsoft can sell you software which you then take responsibility for. A web company like Google can’t.
But there is an error: Microsoft does not sell you the software, you buy a licence of use from Microsoft. This is completely different. In the same way, you can buy from Google the licence of use for GoogleOS. The fact that the bits that compose the software happen to stay on your computer (or not) is totally non-relevant. Actually, in the licence of use, Microsoft could even ask you to not reverse engineer it, to not study it; you could be in situation when you have no way to verify the code you think is there is actually there. Besides, if you have Microsoft Windows installed on your computer, you don’t know if it is relying for some services on some remote servers (of course disconnecting from the Internet will reveal it). You have no way to check what is on your harddisk (a complete operating system or some random bits?) since Windows is not Free Software (it does not give you freedoms).
But, hey, if you want a CD pressed by Google with a shiny GoogleOS logo on it, that simulates its installation on your hard disk, I think Google will be happy to provide it.

Very interesting article: “The long tail of software. Millions of Markets of Dozens”.
Continue Reading

Yesterday I watched Hotel Rwanda, the movie about the 1994 genocide in Rwanda. I have no words to comment it but you must absolutely watch it. Absolutely. And then, since a genocide is NOW happening in Darfur, we must prevent Hotel Darfour. I don’t want to go to watch “Hotel Darfur” in 10 years time and feel again as I was feeling while watching “Hotel Rwanda”. Hotel Darfour is happening now and we must stop it.

(It is an Italian initiative, so I’ll write it in Italian).
LinuxSi.com e’ un sito per raccogliere informazioni su quei negozi che vendono computer con Linux gia` installato, e che magari hanno anche delle persone “linux friendly” che possono dare una mano e fare suggerimenti sulla selezione di un sistema dove far girare Linux.
E` un modo per premiare e aiutare chi pensa a noi.
Essendo nuovo, finora ci sono pochi negozi nel database, ma ci si mette molto poco per aggiungerne uno.