Computing an Ontological Semantics for a Natural Language Fragment

The key objective of the research that has been carried out has been to establish theoretically sound connections between the following two areas: • Computational processing of texts in natural language by means of logical methods • Theories and methods for engineering of formal ontologies We have tried to establish a domain independent “ontological semantics” for relevant fragments of natural language. The purpose of this research is to develop methods and systems for taking advantage of formal ontologies for the purpose of extracting the meaning contents of texts. This functionality is desirable e.g. for future content–based search systems in contrast to today’s keyword based search systems (viz., Google) which rely chiefly on recognition of stated keywords in the targeted text. Logical methods were introduced into semantic theories for natural language already during the 60’s in what is today known as Montague semantics. However, this well–established tradition addresses mainly the domain independent logical structures of language such as quantifiers/determiners by means of logic [18], such as type theory [2]. By contrast this project focuses on the domain–specific parts of language (nouns, verbs, adjectives) introducing formal so–called generative ontologies as semantic target domains for noun– and verb phrases. Such a logico–semantic theory links the meaning of a sentence phrases to nodes in the chosen ontology for the domain.