Mining redundancy in candidate-bearing snippets to improve web question answering

ABSTRACT

Conventional question answering (QA) techniques independently process candidate-bearing snippets to select an exact answer to a question from candidate answers. This paper presents two novel ways of utilizing redundancy in candidate-bearing snippets to help select an exact answer to a question in our Web QA system, i.e., cluster-based language model (CLM-M) and unsupervised SVM classifier (U-SVM) techniques. The comparative experiments demonstrate that the proposed methods significantly outperform the language model-based (LM-M) and supervised SVM-based (S-SVM) techniques that do not utilize this redundancy in the candidate-bearing snippets. Using the CLM-M, the top_1 score is increased from 36.03% (LM-M) to 46.96%; and the top_1 improvement in the U-SVM over the S-SVM is about 23%. Moreover, a cross-model comparison shows that the performance ranking of these models is: U-SVM > CLM-LM > LM-M > S-SVM > R-M (the retrieval-based model).

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INDEX TERMS

Primary Classification:
  H. Information Systems
  H.3 INFORMATION STORAGE AND RETRIEVAL
      H.3.3 Information Search and Retrieval
          Subjects: Selection process

General Terms:
Algorithms, Languages, Performance

Keywords:
data redundancy, language model, question answering, support vector machine