creators_name: Cao, Huanhuan
creators_name: Jiang, Daxin
creators_name: Pei, Jian
creators_name: Chen, Enhong
creators_name: Li, Hang
type: conference_item
datestamp: 2009-04-06 19:08:54
lastmod: 2009-04-22 09:59:55
metadata_visibility: show
title: Towards Context-Aware Search by Learning a Very Large Variable Length Hidden Markov Model from Search Logs
ispublished: pub
full_text_status: public
pres_type: paper
abstract: Capturing the context of a user’s query from the previous queries and clicks in the same session may help understand the user’s information need. A context-aware approach to document re-ranking, query suggestion, and URL recommendation may improve users’ search experience substantially. In this paper, we propose a general approach to context-aware search. To capture contexts of queries, we learn a variable length Hidden Markov Model (vlHMM) from search sessions extracted from log data. Although the mathematical model is intuitive, how to learn a large vlHMM with millions of states from hundreds of millions of search sessions poses a grand challenge. We develop a strategy for parameter initialization in vlHMM learning which can greatly reduce the number of parameters to be estimated in practice. We also devise a method for distributed vlHMM learning under the map-reduce model. We test our approach on a real data set consisting of 1.8 billion queries, 2.6 billion clicks, and 840 million search sessions, and evaluate the effectiveness of the vlHMM learned from the real data on three search applications: document re-ranking, query suggestion, and URL recommendation. The experimental results show that our approach is both effective and efficient.
date: 2009-04
pagerange: 191-191
event_title: 18th International World Wide Web Conference
event_location: Madrid, Spain
event_dates: April 20th-24th, 2009
event_type: conference
refereed: TRUE
citation: Cao, Huanhuan <http://www2009.eprints.org/view/author/Cao=3AHuanhuan=3A=3A.html> and Jiang, Daxin <http://www2009.eprints.org/view/author/Jiang=3ADaxin=3A=3A.html> and Pei, Jian <http://www2009.eprints.org/view/author/Pei=3AJian=3A=3A.html> and Chen, Enhong <http://www2009.eprints.org/view/author/Chen=3AEnhong=3A=3A.html> and Li, Hang <http://www2009.eprints.org/view/author/Li=3AHang=3A=3A.html> (2009) Towards Context-Aware Search by Learning a Very Large Variable Length Hidden Markov Model from Search Logs. In: 18th International World Wide Web Conference, April 20th-24th, 2009, Madrid, Spain.
document_url: http://www2009.eprints.org/20/1/p191.pdf
document_url: http://www2009.eprints.org/20/2/vlHMM.ppt