[Colloq] Hiring Talk **Monday, February 24** 10:30am, 149CN

[Rachel Bates]

College of Computer and Information Science Colloquium

presents:
Javed Alsam
Department of Computer Science
Dartmouth College

who will speak on:
Models for Metasearch


Monday, February 24, 2003
10:30am
149 Cullinane Hall
Northeastern University



ABSTRACT
Given the ranked lists of documents returned by multiple search engines in
response to a given query, the problem of metasearch is to combine these
lists in a way which maximizes the quality of the combination.  In this
talk, we describe two different models for the metasearch problem: one based
on Decision Theory resulting in a Bayesian model and another based on Social
Choice Theory resulting in a multi-candidate election model.  We describe
efficient algorithmic implementations of metasearch strategies in each of
these models, and our experimental results demonstrate that these algorithms
outperform existing ad hoc techniques on benchmark data sets.  Furthermore,
we describe a constrained oracle model for deriving upper bounds on the
potential performance of metasearch algorithms, and we compare and contrast
the performance of our techniques with the limits on metasearch performance
thus derived.  Finally, we describe a machine learning technique which
efficiently improves the quality of metasearch and simultaneously assesses
the quality of the underlying search engines, given user feedback.

Host:  Richard Rasala