tailieunhanh - Báo cáo khoa học: "TEMPORALON TO LOGY IN NATURAL LANGUAGE"

A semantics of linguistic categories like tense, aspect, and certain temporal adverbials, and a theory of their use in defining the temporal relations of events, both require a more complex structure on the domain underlying the meaning representations than is commonly assumed. The paper proposes an ontology based on such notions as causation and consequence, rather than on purely temporal primitives. We claim that any manageable logic or other formal system for natural language temporal descriptions will have to embody such an ontology, as will any usable temporal database for knowledge about events which is to be interrogated using. | TEMPORAL ONTOLOGY IN NATURAL LANGUAGE Marc Moens and Mark Steedman Centre for Cognitive Science t and Dept of Aff Univ of Edinburgh and Dept of Computer and Information Science Univ of Pennsylvania ABSTRACT A semantics of linguistic categories like tense aspect and certain temporal adverbials and a theory of their use in defining the temporal relations of events both require a more complex structure on the domain underlying the meaning representations than is commonly assumed. The paper proposes an ontology based on such notions as causation and consequence rather than on purely temporal primitives. We claim that any manageable logic or other formal system for natural language temporal descriptions will have to embody such an ontology as will any usable temporal database for knowledge about events which is to be interrogated using natural language. 1. Introduction It has usually been assumed that the semantics of temporal expressions is directly related to the linear dimensional conception of time familiar from high-school physics that is to a model based on the number-line. However there are good reasons for suspecting that such a conception is not the one that our linguistic categories are most directly related to. When-clauses provide an example of the mismatch between linguistic temporal categories and a semantics based on such an assumption. Consider the following examples 1 When they built the 39th Street bridge. a .a local architect drew up the plans. b .they used the best materials. c .they solved most of then traffic problems. To map the temporal relations expressed in these examples onto linear time and to try to express the semantics of when in terms of points or intervals possibly associated with events would appear to imply either that when is multiply ambiguous allowing these points or intervals to be temporally related in at least three different ways or that the relation expressed between main and w ien-clauses is one of approximate coincidence . .