Investigation of Question Classifier in Question Answering

In this paper, we investigate how an accurate question classifier contributes to a question answering system. We first present a Maximum Entropy (ME) based question classifier which makes use of head word features and their WordNet hypernyms. We show that our question classifier can achieve the state of the art performance in the standard UIUC question dataset. We then investigate quantitatively the contribution of this question classifier to a feature driven question answering system. With our accurate question classifier and some standard question answer features, our question answering system performs close to the state of the art using TREC corpus.

[1]  Christopher D. Manning,et al.  Generating Typed Dependency Parses from Phrase Structure Parses , 2006, LREC.

[2]  Dietrich Klakow,et al.  Exploring Correlation of Dependency Relation Paths for Answer Extraction , 2006, ACL.

[3]  Dan Klein,et al.  Optimization, Maxent Models, and Conditional Estimation without Magic , 2003, NAACL.

[4]  Mark Andrew Greenwood,et al.  Open-domain question answering , 2005 .

[5]  Zengchang Qin,et al.  Question Classification using Head Words and their Hypernyms , 2008, EMNLP.

[6]  Bernardo Magnini,et al.  Combining Linguistic Processing and Web Mining for Question Answering: ITC-irst at TREC 2004 , 2004, TREC.

[7]  Michael Collins,et al.  Head-Driven Statistical Models for Natural Language Parsing , 2003, CL.

[8]  Tat-Seng Chua,et al.  National University of Singapore at the TREC 13 Question Answering Main Task , 2004, TREC.

[9]  Dan Roth,et al.  Learning Question Classifiers , 2002, COLING.

[10]  Dan Klein,et al.  Improved Inference for Unlexicalized Parsing , 2007, NAACL.

[11]  Dell Zhang,et al.  Question classification using support vector machines , 2003, SIGIR.

[12]  Dan Roth,et al.  Learning question classifiers: the role of semantic information , 2005, Natural Language Engineering.

[13]  Christopher D. Manning,et al.  Incorporating Non-local Information into Information Extraction Systems by Gibbs Sampling , 2005, ACL.

[14]  Eric Nyberg,et al.  Semantic Extensions of the Ephyra QA System for TREC 2007 , 2007, TREC.

[15]  Roberto Basili,et al.  Exploiting Syntactic and Shallow Semantic Kernels for Question Answer Classification , 2007, ACL.

[16]  Michael E. Lesk,et al.  Automatic sense disambiguation using machine readable dictionaries: how to tell a pine cone from an ice cream cone , 1986, SIGDOC '86.

[17]  Soumen Chakrabarti,et al.  Enhanced Answer Type Inference from Questions using Sequential Models , 2005, HLT/EMNLP.

[18]  Dan Klein,et al.  Accurate Unlexicalized Parsing , 2003, ACL.

[19]  Wayne H. Ward,et al.  Question Classification with Support Vector Machines and Error Correcting Codes , 2003, HLT-NAACL.

[20]  Ellen M. Voorhees,et al.  Overview of the TREC 2004 Novelty Track. , 2005 .

[21]  Adam L. Berger,et al.  A Maximum Entropy Approach to Natural Language Processing , 1996, CL.