tailieunhanh - Báo cáo khoa học: "Expanding Verb Coverage in Cyc With VerbNet"

A robust dictionary of semantic frames is an essential element of natural language understanding systems that use ontologies. However, creating lexical resources that accurately capture semantic representations en masse is a persistent problem. Where the sheer amount of content makes hand creation inefficient, computerized approaches often suffer from over generality and difficulty with sense disambiguation. | Expanding Verb Coverage in Cyc With VerbNet Clifton J. McFate Northwestern University Evanston II. USA. c-mcfate@ Abstract A robust dictionary of semantic frames is an essential element of natural language understanding systems that use ontologies. However creating lexical resources that accurately capture semantic representations en masse is a persistent problem. Where the sheer amount of content makes hand creation inefficient computerized approaches often suffer from over generality and difficulty with sense disambiguation. This paper describes a semi-automatic method to create verb semantic frames in the Cyc ontology by converting the information contained in VerbNet into a Cyc usable format. This method captures the differences in meaning between types of verbs and uses existing connections between WordNet VerbNet and Cyc to specify distinctions between individual verbs when available. This method provides 27 909 frames to OpenCyc which currently has none and can be used to extend ResearchCyc as well. We show that these frames lead to a 20 increase in sample sentences parsed over the Research Cyc verb lexicon. 1 Introduction The Cyc1 knowledge base represents general purpose knowledge across a vast array of domains. Low level event and individual facts are contained in larger definitional hierarchical representations and contextualized through microtheories Matuszek et al 2006 . Higher order predicates built into Cyc s formal language CycL allow efficient inferencing about context and meta-language reasoning above and beyond first-order logic rules Ramachandran et al 2005 . Because of the expressiveness and size of the ontology Cyc has been used in NL applications 1 http cyc including word sense disambiguation and rule acquisition by reading Curtis Cabral Baxter 2006 Curtis et al 2009 . Such applications use NL-to-Cycl parsers which use Cyc semantic frames to convert natural language into Cyc representations. These frames .