Target Language-Aware Constrained Inference for Cross-lingual Dependency Parsing

Tao Meng, Nanyun Peng, Kai-Wei Chang

Abstract
Prior work on cross-lingual dependency parsing often focuses on capturing the commonalities between source and target languages and overlook the potential to leverage the linguistic properties of the target languages to facilitate the transfer. In this paper, we show that weak supervisions of linguistic knowledge for the target languages can improve a cross-lingual graph-based dependency parser substantially. Specifically, we explore several types of corpus linguistic statistics and compile them into corpus-statistics constraints to facilitate the inference procedure. We propose new algorithms that adapt two techniques, Lagrangian relaxation and posterior regularization, to conduct inference with corpus-statistics constraints. Experiments show that the Lagrangian relaxation and posterior regularization techniques improve the performances on 15 and 17 out of 19 target languages, respectively. The improvements are especially large for the target languages that have different word order features from the source language.
Anthology ID:
D19-1103
Volume:
Proceedings of the 2019 Conference on Empirical Methods in Natural Language Processing and the 9th International Joint Conference on Natural Language Processing (EMNLP-IJCNLP)
Month:
November
Year:
2019
Address:
Hong Kong, China
Editors:
Kentaro Inui, Jing Jiang, Vincent Ng, Xiaojun Wan
Venues:
EMNLP | IJCNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
1117–1128
Language:
URL:
https://aclanthology.org/D19-1103
DOI:
10.18653/v1/D19-1103
Bibkey:
Cite (ACL):
Tao Meng, Nanyun Peng, and Kai-Wei Chang. 2019. Target Language-Aware Constrained Inference for Cross-lingual Dependency Parsing. In Proceedings of the 2019 Conference on Empirical Methods in Natural Language Processing and the 9th International Joint Conference on Natural Language Processing (EMNLP-IJCNLP), pages 1117–1128, Hong Kong, China. Association for Computational Linguistics.
Cite (Informal):
Target Language-Aware Constrained Inference for Cross-lingual Dependency Parsing (Meng et al., EMNLP-IJCNLP 2019)
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PDF:
https://preview.aclanthology.org/nschneid-patch-4/D19-1103.pdf
Attachment:
 D19-1103.Attachment.pdf
Code
 MtSomeThree/CrossLingualDependencyParsing
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