[Colloquium] Matveeva/Dissertation Defense/2-19-08

[Margaret Jaffey]

			Department of Computer Science/The University of Chicago

						*** Dissertation Defense ***


Candidate:  Irina Matveeva

Date:  Tuesday, February 19, 2008

Time and Location:  1:00 p.m. in Ryerson 255

Title:  Generalized Latent Semantic Analysis for Document Representation

Abstract:
Document representation has a large impact on the performance of
document retrieval and clustering algorithms. Since content words can  
be combined into semantic classes there has been a considerable  
interest in low-dimensional term and document representations. We  
developed the Generalized Latent Semantic Analysis (GLSA) framework to  
extend the applicability of the idea of the latent semantic space  
analysis with spectral embedding. GLSA uses linguistically motivated  
measures of similarity between words and employs different  
dimensionality reduction techniques to preserve them.

Most language modelling and dimensionality reduction approaches are  
applied to the full vocabulary. However, semantics and syntax provide  
a theoretical justification for treating subsets of the vocabulary  
differently. Moreover, the theoretical justification of GLSA suggest  
that it is most appropriate applied to a subset of the vocabulary  
comprised of content words. Therefore, I propose to use GLSA with a  
hybrid approach to document indexing. My goal is to keep the notion of  
latent semantic concepts and at the same time preserve the specifics  
of the document collection. Our experiments show that GLSA improves  
the results of the similarity based document classification and  
clustering algorithms and text segmentation algorithms.

Candidate's Advisers: Gina-Anne Levow, Partha Niyogi

A draft copy of Ms. Matveeva's dissertation will be available soon in  
Ry 156.

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Margaret P. Jaffey                             margaret at cs.uchicago.edu
Department of Computer Science
Student Support Rep (Ry 156)        (773) 702-6011
The University of Chicago                  http://www.cs.uchicago.edu
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