tailieunhanh - Báo cáo khoa học: "Exploiting Web Redundancy for Answer Validation"

Answer Validation is an emerging topic in Question Answering, where open domain systems are often required to rank huge amounts of candidate answers. We present a novel approach to answer validation based on the intuition that the amount of implicit knowledge which connects an answer to a question can be quantitatively estimated by exploiting the redundancy of Web information. Experiments carried out on the TREC-2001 judged-answer collection show that the approach achieves a high level of performance (. 81% success rate). The simplicity and the efficiency of this approach make it suitable to be used as a module in. | Is It the Right Answer Exploiting Web Redundancy for Answer Validation Bernardo Magnini Matteo Negri Roberto Prevete and Hristo Tanev ITC-Irst Centro per la Ricerca Scientifica e Tecnologica magnini negri prevete tanev @ Abstract Answer Validation is an emerging topic in Question Answering where open domain systems are often required to rank huge amounts of candidate answers. We present a novel approach to answer validation based on the intuition that the amount of implicit knowledge which connects an answer to a question can be quantitatively estimated by exploiting the redundancy of Web information. Experiments carried out on the TREC-2001 judged-answer collection show that the approach achieves a high level of performance . 81 success rate . The simplicity and the efficiency of this approach make it suitable to be used as a module in Question Answering systems. 1 Introduction Open domain question-answering QA systems search for answers to a natural language question either on the Web or in a local document collection. Different techniques varying from surface patterns Subbotin and Subbotin 2001 to deep semantic analysis Zajac 2001 are used to extract the text fragments containing candidate answers. Several systems apply answer validation techniques with the goal of filtering out improper candidates by checking how adequate a candidate answer is with respect to a given question. These approaches rely on discovering semantic relations between the question and the answer. As an example Harabagiu and Maiorano 1999 describes answer validation as an abductive inference process where an answer is valid with respect to a question if an explanation for it based on background knowledge can be found. Although theoretically well motivated the use of semantic techniques on open domain tasks is quite expensive both in terms of the involved linguistic resources and in terms of computational complexity thus motivating a research on alternative solutions to the problem.