The Semantic Representation of Temporal Expressions in Text

Temporal expressions—references to points in time or periods of time—are widespread in text, and their proper interpretation is essential for any natural language processing task that requires the extraction of temporal information. Work on the interpretation of temporal expressions in text has generally been pursued in one of two paradigms: the formal semantics approach, where an attempt is made to provide a well-grounded theoretical basis for the interpretation of these expressions, and the more pragmatically-focused approach represented by the development of the TIMEX2 standard, with its origins in work in information extraction. The former emphasises formal elegance and consistency; the latter emphasises broad coverage for practical applications. In this paper, we report on the development of a framework that attempts to integrate insights from both perspectives, with the aim of achieving broad coverage of the domain in a well-grounded manner from a formal perspective. We focus in particular on the development of a compact notation for representing the semantics of underspecified temporal expressions that enables the component-level evaluation of systems.