Experiments with Query Expansion in the RAPOSA (FOX) Question Answering System

Luís Sarmento, Jorge Teixeira, Eugénio C. Oliveira
2008 Conference and Labs of the Evaluation Forum  
In this paper we present the results of applying a statistical query expansion method on the retrieval stage of a QA system for Portuguese (RAPOSA). Our approach involves expanding queries for event-related or action-related factoid questions using a verb thesaurus automatically generated using information extracted from large corpora. We show that our expansion approach improves QA recall when compared with applying expansion based on a simple form of stemming, while simultaneously requiring
more » ... e analysis of only 30% as many text snippets. However, we were not able to outperform the recall obtained using an even simpler expansion method, which nevertheless achieves lower precision and requires analyzing many more text snippets. We conclude by observing that a more thorough analysis of the usefulness of our approach on QA performance requires improving other stages of the QA pipeline which currently impose significant limitations on the overall performance of the system.
dblp:conf/clef/SarmentoTO08a fatcat:uwj3dkh7g5cend3zfsnab4mx5u