tailieunhanh - Báo cáo khoa học: "Generation of VP Ellipsis: A Corpus-Based Approach"

We present conditions under which verb phrases are elided based on a corpus of positive and negative examples. Factor that affect verb phrase ellipsis include: the distance between antecedent and ellipsis site, the syntactic relation between antecedent and ellipsis site, and the presence or absence of adjuncts. Building on these results, we examine where in the generation architecture a trainable algorithm for VP ellipsis should be located. | Generation of VP Ellipsis A Corpus-Based Approach Daniel Hardt Copenhagen Business School Copenhagen Denmark dh@ Owen Rambow AT T Labs - Research Florham Park NJ USA rambow@ Abstract We present conditions under which verb phrases are elided based on a corpus of positive and negative examples. Factor that affect verb phrase ellipsis include the distance between antecedent and ellipsis site the syntactic relation between antecedent and ellipsis site and the presence or absence of adjuncts. Building on these results we examine where in the generation architecture a trainable algorithm for VP ellipsis should be located. We show that the best performance is achieved when the trainable module is located after the realizer and has access to surface-oriented features error rate of . 1 Introduction While there is a vast theoretical and computational literature on the interpretation of elliptical forms there has been little study of the generation of In this paper we focus on Verb Phase Ellipsis VPE in which a verb phrase is elided with an auxiliary verb left in its place. Here is an example 1 In 1980 18 of federal prosecutions concluded at trial in 1987 only 9 did. Here the verb phase concluded at trial is omitted and the auxiliary did appears in its place. The 1We would like to thank Marilyn Walker three reviewers for a previous submission and three reviewers for this submission for helpful comments. basic condition on VPE is clear from the litera-ture 2 there must be an antecedent VP that is identical in meaning to the elided VP. Furthermore it seems clear that the antecedent must be sufficiently close to the ellipsis site in a sense to be made precise . This basic condition provides a beginning of an account of the generation of VPE. However there is more to be said as is shown by the following examples 2 Ernst Young said Eastern s plan would miss projections by 100 million. Goldman said Eastern would miss the same mark by at least