Hostname: page-component-78c5997874-v9fdk Total loading time: 0 Render date: 2024-11-10T15:04:37.886Z Has data issue: false hasContentIssue false

A reestimation algorithm for probabilistic dependency grammars

Published online by Cambridge University Press:  01 September 1999

SEUNGMI LEE
Affiliation:
Department of Computer Science, Center for Artificial Intelligence Research, Korea Advanced Institute of Science and Technology, 373-1 Kusung-Dong YuSung-Gu Taejon 305-701 Korea; e-mail: leesm@world.kaist.ac.kr, kschoi@world.kaist.ac.kr
KEY-SUN CHOI
Affiliation:
Department of Computer Science, Center for Artificial Intelligence Research, Korea Advanced Institute of Science and Technology, 373-1 Kusung-Dong YuSung-Gu Taejon 305-701 Korea; e-mail: leesm@world.kaist.ac.kr, kschoi@world.kaist.ac.kr

Abstract

A probabilistic parameter reestimation algorithm plays a key role in the automatic acquisition of stochastic grammars. In the case of context-free phrase structure grammars, the inside-outside algorithm is widely used. However, it is not directly applicable to Probabilistic Dependency Grammar (PDG), because PDG is not based on constituents but on a head-dependent relation between pairs of words. This paper presents a reestimation algorithm which is a variation of the inside-outside algorithm adapted to probabilistic dependency grammar. The algorithm can be used either to reestimate the probabilistic parameters of an existing dependency grammar, or to extract a PDG from scratch. Using the algorithm, we have learned a PDG from a part-of-speech-tagged corpus of Korean, which showed about 62·82% dependency accuracy (the percentage of correct dependencies) for unseen test sentences.

Type
Research Article
Copyright
© 1999 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)