Sounds like excellent work Luca! I'm sure the online service will be of great use to the community, and in ways that cannot be anticipated at this time.

Alain Désilets

-----Original Message-----
From: on behalf of Luca de Alfaro
Sent: Wed 5/28/2008 7:06 PM
To: Research into Wikimedia content and communities
Subject: [Wiki-research-l] Three techreps: assigning trust to Wikipediacontent, and reputation, contributions of authors

Dear All,

we have three new techreps available:

   - Robust Content-Driven
that the content-driven reputation we proposed in a WWW 2007 paper can
   be made robust to Sybil ("sock-puppet") and other coordinated attacks.  In
   WWW 2007, we proposed "content-driven reputation" for Wikipedia authors,
   where authors gain reputation if their contributions are preserved, and lose
   reputation if their contributions are quickly undone.  The original
   algorithms were very prone to attacks; we show here that they can be made

   - Assigning Trust to Wikipedia
computing the trust of Wikipedia text on the basis of the
   reputation of the author, and the reputation of the people who revised the
   text.   We display text trust by coloring text background.  Many of you have
   seen the on-line demo for the English Wikipedia, at . This is an improved version of a November
   2007 techrep on the same topic.  In this improved techrep, we show how the
   trust system can be made resistant to attacks.

   - Measuring Author Contributions to the
and compares various ways for measuring the contribution of
   individual authors to the Wikipedia.  We have our own favorite; read more to
   find out :-)

In these months, we have been busy working at
an open-source tool for assigning reputation to wiki authors and trust to
wiki content.  We already have a batch (or "off-line") system, which can
compute reputation and trust based on wiki dumps, such as the Wikipedia
dumps made available by the Wikimedia Foundation.  We are developing an
"on-line" system, which can assign reputation and trust in real-time, as
edits are made.  One of our chief concerns in developing an on-line system
was to ensure that it was robust to attack, and we believe we have made
progress in this direction, as reported in the above techreps.  We are now
proceeding with the implementation; my guess is that we will have a
prototype in a month or so.

By the way, the "batch" part of  WikiTrust <>  can
be easily adapted to carry out various analysis tasks.  Basically, it walks
over all revisions of every page of a wiki, and it contains an efficient
text analysis engine that tells you precisely how text was changed between
versions. So, it is easy to use WikiTrust as a platform to write analysis
algorithms for wikis: you don't have to worry about the boring tasks of
reading and parsing markup language, and computing text diffs in a
reasonable way; you can concentrate on the details of the specific analysis
you want to do.  It is all open source, and we welcome developers or people
interested in it.

All the best,

Luca (with Ian, Bo, and the other wikitrusters).