tailieunhanh - Báo cáo khoa học: "Deriving Verbal and Compositional Lexical Aspect for NLP Applications"

Verbal and compositional lexical aspect provide the underlying temporal structure of events. Knowledge of lexical aspect, ., (a)telicity, is therefore required for interpreting event sequences in discourse (Dowty, 1986; Moens and Steedman, 1988; Passoneau, 1988), interfacing to temporal databases (Androutsopoulos, 1996), processing temporal modifiers (Antonisse, 1994), describing allowable alternations and their semantic effects (Resnik, 1996; Tenny, 1994), and selecting tense and lexical items for natural language generation ((Dorr and Olsen, 1996; Klavans and Chodorow, 1992), cf. (Slobin and Bocaz, 1988)). . | Deriving Verbal and Compositional Lexical Aspect for NLP Applications Bonnie J. Dorr and Mari Broman Olsen University of Maryland Institute for Advanced Computer Studies . Williams Building College Park MD 20742 USA bonnie molsen@ Abstract Verbal and compositional lexical aspect provide the underlying temporal structure of events. Knowledge of lexical aspect . a telicity is therefore required for interpreting event sequences in discourse Dowty 1986 Moens and Steedman 1988 Passoneau 1988 interfacing to temporal databases Androutsopoulos 1996 processing temporal modifiers An-tonisse 1994 describing allowable alternations and their semantic effects Resnik 1996 Tenny 1994 and selecting tense and lexical items for natural language generation Dorr and Olsen 1996 Klavans and Chodorow 1992 cf. Slobin and Bo-caz 1988 . We show that it is possible to represent lexical aspect both verbal and compositional on a large scale using Lexical Conceptual Structure LCS representations of verbs in the classes cataloged by Levin 1993 . We show how proper consideration of these universal pieces of verb meaning may be used to refine lexical representations and derive a range of meanings from combinations of LCS representations. A single algorithm may therefore be used to determine lexical aspect classes and features at both verbal and sentence levels. Finally we illustrate how knowledge of lexical aspect facilitates the interpretation of events in NLP applications. 1 Introduction Knowledge of lexical aspect how verbs denote situations as developing or holding in time is required for interpreting event sequences in discourse Dowty 1986 Moens and Steedman 1988 Passoneau 1988 interfacing to temporal databases Androutsopou-los 1996 processing temporal modifiers Antonisse 1994 describing allowable alternations and their semantic effects Resnik 1996 Tenny 1994 and for selecting tense and lexical items for natural language generation Dorr and Olsen. 1996 Klavans and Chodorow