Title
Policy Gradient As A Proxy For Dynamic Oracles In Constituency Parsing
Abstract
Dynamic oracles provide strong supervision for training constituency parsers with exploration, but must be custom defined for a given parser's transition system. We explore using a policy gradient method as a parser-agnostic alternative. In addition to directly optimizing for a tree-level metric such as F1, policy gradient has the potential to reduce exposure bias by allowing exploration during training; moreover, it does not require a dynamic oracle for supervision. On four constituency parsers in three languages, the method substantially outperforms static oracle likelihood training in almost all settings. For parsers where a dynamic oracle is available (including a novel oracle which we define for the transition system of Dyer et al. (2016)), policy gradient typically recaptures a substantial fraction of the performance gain afforded by the dynamic oracle.
Year
DOI
Venue
2018
10.18653/v1/p18-2075
PROCEEDINGS OF THE 56TH ANNUAL MEETING OF THE ASSOCIATION FOR COMPUTATIONAL LINGUISTICS, VOL 2
DocType
Volume
Citations 
Journal
abs/1806.03290
2
PageRank 
References 
Authors
0.37
1
2
Name
Order
Citations
PageRank
Daniel Fried1837.69
Dan Klein28083495.21