Statistical Machine Translation for Query Expansion in Answer Retrieval

We present an approach to query expansion in answer retrieval that uses Statistical Machine Translation (SMT) techniques to bridge the lexical gap between questions and answers. SMT-based query expansion is done by i) using a full-sentence paraphraser to introduce synonyms in context of the entire query, and ii) by translating query terms into answer terms using a full-sentence SMT model trained on question-answer pairs. We evaluate these global, context-aware query expansion techniques on tfidf retrieval from 10 million question-answer pairs extracted from FAQ pages. Experimental results show that SMTbased expansion improves retrieval performance over local expansion and over retrieval without expansion.

• Type: Conference
• Year: 2007
• Where: ACL
• Authors: Stefan Riezler, Alexander Vasserman, Ioannis Tsochantaridis, Vibhu O. Mittal, Yi Liu
• Keywords: ACL 2007, Computational Linguistics, Context-aware Query Expansion, Query Expansion, SMT-based Query Expansion