Dear All, *The Pascal Challenge on Computer-Assisted Stemmatology* evaluates methods for reconstructing the family-tree of a group of related documents. Such a family-tree corresponds to a) a clustering hierarchy, where joined subgroups make subtrees; b) a causal/graphical model of interdocument dependencies; c) a network of information flow among the documents; d) a phylogenetic tree; etc. Many of the applicable techniques are often applied in unsupervised scenarios. The Challenge presents an opportunity to compare different methods and approaches in a supervised and objective fashion (and to show that your approach is the best!). A prototypical example illustrating the problem is as follows: A top AI researcher has finally concluded (after, what, 20 years?) that the statement "Tweety is a bird" is true. The rumour of this fact spreads around like wildfire, becoming distorted along the way. After a while, a set of scientists report respectively that: "Sweety is a bird"; "Sweety has a bird"; and "Tweety is a nerd". Can we deduce how the information spread among the scientists? (No, we are not interested to know if Tweety can fly... Sorry.) Participation is open to all. More information can be found on the web-page of the Challenge: http://www.cs.helsinki.fi/teemu.roos/casc/ The schedule is as follows: First-phase data available October 6, 2006 Second-phase data available November 30, 2006 Validation data available * February 20, 2007 * Submission deadline March 30, 2007 Results April 30, 2007 So as you see, this is a good time to check out he challenge since we just made available the validata set and a correct (and an incorrect) solution for it: http://www.cs.helsinki.fi/teemu.roos/casc/example.html We invite applications of established and, in particular, novel approaches to stemmatology, including but of course not restricted to hierarchical clustering, graphical modeling, link analysis, phylogenetics, string-matching, etc. Organizers: * Teemu Roos, Helsinki Inst. for Information Technology * Tuomas Heikkilä, Dept. of History, University of Helsinki * Petri Myllymäki, Dept. of CS, University of Helsinki On behalf of the organizers, Teemu Roos Helsinki Institute for Information Technology ---------------------------------------------- CLASS-L list. Instructions: http://www.classification-society.org/csna/lists.html#class-l