Accommodating Negation in an Efficient Event-based Natural Language Query Interface to the Semantic Web

Shane Peelar, Richard Frost


Although The Semantic Web was built with the Open World Assumption in mind, there are many cases where the Closed World Assumption would be a better fit. This is unfortunate because the OWA prevents rich queries involving negation from taking place, even in contexts where it would be appropriate. In this paper we present an English Natural Language Query Interface to event-based triplestores based on Compositional Semantics that can support both open and closed world semantics with “drop-in” denotations for “no”, “not”, “non”, and “the least”. Where closed world semantics are not appropriate, omitting these denotations is sufficient to restore the OWA. The result is a highly expressive compositional semantics supporting complex linguistic constructs such as chained prepositional phrases, n-ary transitive verbs, superlative phrases, and negation, suitable for expert systems and knowledge bases.


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