RALI-OLST Weekly Talks

Relating Dependent Indexes Using Dempster-Shafer Theory

Lixin Shi (shilixin <at> iro (point) umontreal (point) ca)

RALI, DIRO

Wednesday 1 October 2008 at 11:30 AM

Salle 3195, Pavillon André-Aisenstadt


Traditional information retrieval (IR) approaches assume that the indexing terms are independent, which is not true in reality. Although some previous studies have tried to consider term relationships, strong simplifications had to be made at the very basic indexing step, namely, dependent terms are assigned independent counts or probabilities. In this study, we propose to consider dependencies between terms using Dempster-Shafer theory of evidence. An occurrence of a string in a document is considered to represent the set of all the terms implied in it. Probability is assigned to such a set of terms instead of individual terms. During query evaluation phase, a part of the probability of a set can be transferred to those of the query that are related, allowing us to integrate language-dependent relations in IR. This approach has been tested on several Chinese IR collections. Our experimental results show that our model can outperform the existing state-of-the-art approaches. The proposed method can be used as a general way to consider different types of relationship between terms and for other languages.



Join with Zoom at this url.
Meeting ID: 916 9097 5818, 𝑷𝒂𝒔𝒔𝒄𝒐𝒅𝒆: 343273.
Phone numbers: https://umontreal.zoom.us/u/abitNZzLg.
One tap mobile: +14388097799,,91690975818#,,,,,,0#,,343273#


To receive weekly talk announcements, please send an e-mail to majordomo@iro.umontreal.ca. Simply write a message containing the single line 'subscribe ralli' (without the quotes).

See all the weekly talks for the year:

1991 1992 1993 1994 1995 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021