Document-Level Event Description and Decomposition

Abstract

Events have structure. At the token level, this structure is characterized to a large extent by the relations that individual events bear to their participants and to their subevents. At the type level, kinds of events and semantic roles are often organized into hierarchical ontologies. This thesis studies type- and token-level event structure in the context of full documents, where an account of a single event may span multiple sentences and may involve diverse kinds of subevents and participants. We explore ways of making event structure at both levels more transparent and more extensible through two broad approaches: decompositions of events into simpler events and event properties, and natural language descriptions of events and event ontologies.