AQUA - Ontology-based Question Answering System

This paper describes AQUA, an experimental question answering system. AQUA combines Natural Language processing (NLP), Ontologies, Logic, and Information Retrieval technologies in a uniform framework. AQUA makes intensive use of an ontology in several parts of the question answering system. The ontology is used in the refinement of the initial query, the reasoning process (a generalization or specialization process using classes and subclasses from the ontology), and in the novel similarity algorithm. The similarity algorithm, is a key feature of AQUA. It is used to find similarities between relations/concepts in the translated query and relations/concepts in the ontological structures. The similarities detected then allow the interchange of concepts or relations in a logic formulae corresponding to the user query.