BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Consensus finding\, exponential models and infinite rankings - Dr 
 Marina Meila (University of Washington)
DTSTART:20081112T130000Z
DTEND:20081112T140000Z
UID:TALK15194@talks.cam.ac.uk
CONTACT:Zoubin Ghahramani
DESCRIPTION:This talk is concerned with summarizing -- by means of statist
 ical\nmodels -- of data that expresses preferences. This data is typically
  a set of rankings of n items by a panel of experts\; the simplest summary
  is the "consensus ranking"\, or the "centroid" of the set of\nrankings. S
 uch problems appear in many tasks\, ranging from combining voter preferenc
 es to boosting of search engines.\n\nWe study the problem in its more gene
 ral form of estimating a\nparametric model known as the Generalized Mallow
 s (GM) model. I will present an exact estimation algorithm\, non-polynomia
 l in theory\, but extremely effective in comparison with existing algorith
 ms. From a statistical point of view\, we show that the GM model is an exp
 onential family\, and introduce the conjugate prior for this model class.\
 n\nThen we introduce the infinite GM model\, corresponding to "rankings" o
 ver an infinite set of items\, and show that this model is both elegant an
 d of practical significance. Finally\, the talk will touch upon the subjec
 t of multimodal distributions and clustering.\n\nJoint work with: Bhushan 
 Mandhani\, Le Bao\, Kapil Phadnis\, Arthur\nPatterson and Jeff Bilmes  \n\
 n
LOCATION:Engineering Department\, CBL Room 438
END:VEVENT
END:VCALENDAR