A Heuristic Model for Treatment of Vague Time Descriptions

Abstract

In this paper we present a heuristic model which is capable of dealing with vague time references and modifiers. Basically, vagueness appears in two different ways: a reference can be incomplete or the degree of concreteness may be low. In order to overcome this lack of information we propose the application of defaults and probability distributions for the computation of possibility estimates about the temporal constellation of events. Conceptual descriptions of time references are assumed to be derivable from natural language expressions. They are mapped onto an appropriate numeric form providing the unification of descriptions with different types of units and concreteness. Some operations are defined realizing reasoning processes to determine adequate expectations about events characterized by several temporal descriptions. As we will show, this method provides a basis for treating questions about potential events, which cannot be answered on the basis of a true/false mechanism. Finally, some ideas about the verbalization of the numeric representation are discussed.