Answer Verification for Improved Precision in a

VOCAULA, for Verification Of Candidate Answers Using Linguistic Analysis, is an answer verification system and methodology developed as a component for a larger Web-based question answering system, Aranea. Aranea uses the high recall avail-able by applying information retrieval techniques to the World Wide Web to increase domain coverage. This approach generates multiple candidate answers for any ques-tion; VOCAULA picks the best of these candidates by considering linguistic constraints present in the question and comparing these to supporting information for the candi-date answers. Although intended for a particular system, this component's modular design allows it to easily integrate into any question answering system which is based on high recall from large corpora. In evaluation against a set of TREC test questions, VOCAULA increased the number of correct answers by nearly ten percent over the base Aranea system. This is a modest gain, but it shows that answer verification should play a part in any question answering system using an information retrieva