Question focus extraction and answer passage retrieval

Question Analysis is an important task in Question Answering Systems (QAS). It consists generally in identifying the semantic type of the question and extracting the main focus of the question. The goal is to better specify the required information by the question. In this context and as part of a framework aiming to implement an Arabic opinion QAS for political debates, this paper addresses the problem of defining the focus of opinion questions and proposes particularly an approach for extracting the focus of attitude questions. The proposed approach is based on semi-automatically constructed lexico-syntactic patterns. Furthermore, the paper presents an adapted Vector Space Model (VSM) based method to retrieve candidate answer passages from a transcribed TV political show. Several experiments were carried out and showed that the focus extraction approach has achieved over 72% as F1 score for holder and target extraction, and has improved the baseline passage retrieval task by over than 25%.