University of Illinois Urbana-Champaign

Unsupervised query expansion for theme queries by exploration and fusion

Li, Sha

Content Files
LI-THESIS-2019.pdf

Permalink

https://hdl.handle.net/2142/105828

Description

Title
Unsupervised query expansion for theme queries by exploration and fusion
Author(s)
Li, Sha
Issue Date
2019-07-16
Director of Research (if dissertation) or Advisor (if thesis)
Han, Jiawei
Department of Study
Computer Science
Discipline
Computer Science
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
M.S.
Degree Level
Thesis
Date of Ingest
2019-11-26T20:49:31Z
Keyword(s)
  • Information retrieval
  • query expansion
  • contextual bandit algorithm
Abstract
Theme queries are a subtype of informational queries that cover broader topics than those expressed explicitly in the query terms. For this type of query, it is natural to resort to query reformation techniques such as query expansion. While traditional query expansion may be used to improve the query, new query terms are ranked only once and no verification of quality of the new ranking is made. In comparison, we propose to address such queries with iterative unsupervised expansion: adaptive query exploration and rank fusion. In the lack of human labels, we combine multiple signals to help select the best expansion candidates and further use rank fusion to generate the final ranking and the new query with discretion. The two modules iteratively improve each other: the rank fusion results provide an estimated ranking improvement score to guide the query exploration module and the query exploration modules selects the most promising query variants to add to the fusion. Experiments on the NYT dataset and the Washington Post dataset confirm that our proposed method successfully improves upon baseline methods.
Graduation Semester
2019-08
Type of Resource
text
Permalink
http://hdl.handle.net/2142/105828
Copyright and License Information
Copyright 2019 Sha Li

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Dissertations and Theses - Computer Science
Dissertations and Theses from the Siebel School of Computer Science
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Graduate Theses and Dissertations at Illinois