[Colloquium] REMINDER: Research at TTIC: Ofer Meshi, TTIC

[Dawn Ellis]

When:     Friday, February 20, 2015 at noon

Where:    TTIC, 6045 S Kenwood Avenue, 5th Floor, Room 526

Who:       Ofer Meshi, TTIC

Title:       Title: Structured Ranking

Abstract:

Ranking a set of objects is an important task in many applications, such as
web search, document retrieval, and link prediction in a network. The
ranking problem can be formulated as a prediction problem, where given a
query and a set of objects, the model predicts a permutation of the objects
that best fits the query. In most existing methods the model assigns a
score to each individual object and outputs the list of objects sorted by
their scores. However, this approach fails to take into account
dependencies between objects, which often arise in applications. For
example, some pairs of objects may have similar ranks.
In this work we propose a framework for modeling such dependency structure
in the context of a ranking model. In particular, we show how structured
predictors, which model rich dependencies, can be trained to optimize a
ranking loss based on the Area Under the ROC Curve (AUC), and we
demonstrate the improved ranking quality produced by such models compared
to unstructured ones. We then introduce several extensions of our basic
framework and study their computational and modeling benefits.

Based on joint work with Nir Rosenfeld, Danny Tarlow and Amir Globerson.




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Research at TTIC Seminar Series

TTIC is hosting a weekly seminar series presenting the research currently
underway at the Institute. Every week a different TTIC faculty member will
present their research.  The lectures are intended both for students
seeking research topics and adviser, and for the general TTIC and
University of Chicago communities interested in hearing what their
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Speaker details can be found at: http://www.ttic.edu/tticseminar.php.

For additional questions, please contact David McAllester at
mcallester at ttic.edu


-- 
*Dawn Ellis*
Administrative Coordinator,
Bookkeeper
773-834-1757
dellis at ttic.edu

TTIC
6045 S. Kenwood Ave.
Chicago, IL. 60637
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