Document Filtering and Ranking Using Syntax and Statistics for Open Domain Question Answering

Document Filtering and Ranking Using Syntax and Statistics for Open Domain Question Answering. This paper presents a strategy for a syntax based ranking of documents specifically oriented to Question Answering (QA). This strategy should limit the number of documents, processed by an answer extraction module of an syntax oriented QA system. Several measures for statistical scoring of expressions are presented and evaluated on 400 factoid questions from the TREC-12 competition. We prove that syntax based document filtering can outperform classical inverse document frequency approaches (idf)