Computational Event Structures Part I Getting directional: Incremental changes, participanthood, and the underlying structure of events

In this paper, we present a general computational structure to account for the aspectual dimension of events. The construction is centered on the interaction of entities partaking in events to reach a final state accessible only if the final transition leading to that state can conclude. This amounts to say that in sentences denoting an activity or an accomplishment, an entity (fully lexicalized or not) is always acting as a delimiter of the final transition, thereby allowing it to conclude. When this entity is fully lexicalized and bounded (i.e. measurable in the sense of Tenny (1990) and as developped more precisely by Verkuyl (1993) ), the sentence has an accomplishment reading. When it is unbounded or when it is not fully lexicalized, the sentence has an activity reading. We believe this computational construction to express in a nice way the close relationship between these two aspectual classes (as noted by Dowty (1979, p. 61) , and Pustejovsky (1991b) among others) without having to incorporate these situational categories in our description. Our approach is also characterized by the fact thematic roles are derivative constructs instead of labels imposed by meaning postulates (as in many neo-davidsonian approaches). Copyright © Massachusetts Institute of Technology, 1994 This article describes research done at the Department of Brain & Cognitive Sciences of the Massachusetts Institute of Technology. Support for the research is provided by a Postdoctoral fellowship to the author from the Social Sciences and Humanities Research Council of Canada #756-93-0129.