Abstract

Lexical co-occurrence statistics axe becoming widely used in the syntaetic analysis of unconstrained text. However, anal- yses based solely on lexical relationships suffer from sparse- ness of data: it is sometimes necessary to use a less informed model in order to reliably estimate statistical parameters. For example. the "lexical association" stralegy for resolving am- biguous prepositional phrase attachments [Hindle and Rooth. 1991 ] taes into account only the attachment site la verb or its direct object) and the preposition, ignoring the objecl of the preposition, We investigated an extension of the lexical association strategy to make use of noun class information, thus permitting a disambiguation sxategy to take more information into account. Although in preliminary experiments the extended strategy did not yield impwved performance over lexical association alone. a qualitative analysis of the results suggests that the problem lies not in the noun class information, but rather in the multipiletry oflass available for each noun in the absence of sense disambiguation, This suggests several possible revisions of our proposal.

Citations