Low-Resource Syntactic Transfer with Unsupervised Source Reordering

Mohammad Sadegh Rasooli, Michael Collins


Abstract
We describe a cross-lingual transfer method for dependency parsing that takes into account the problem of word order differences between source and target languages. Our model only relies on the Bible, a considerably smaller parallel data than the commonly used parallel data in transfer methods. We use the concatenation of projected trees from the Bible corpus, and the gold-standard treebanks in multiple source languages along with cross-lingual word representations. We demonstrate that reordering the source treebanks before training on them for a target language improves the accuracy of languages outside the European language family. Our experiments on 68 treebanks (38 languages) in the Universal Dependencies corpus achieve a high accuracy for all languages. Among them, our experiments on 16 treebanks of 12 non-European languages achieve an average UAS absolute improvement of 3.3% over a state-of-the-art method.
Anthology ID:
N19-1385
Volume:
Proceedings of the 2019 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, Volume 1 (Long and Short Papers)
Month:
June
Year:
2019
Address:
Minneapolis, Minnesota
Editors:
Jill Burstein, Christy Doran, Thamar Solorio
Venue:
NAACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
3845–3856
Language:
URL:
https://aclanthology.org/N19-1385
DOI:
10.18653/v1/N19-1385
Bibkey:
Cite (ACL):
Mohammad Sadegh Rasooli and Michael Collins. 2019. Low-Resource Syntactic Transfer with Unsupervised Source Reordering. In Proceedings of the 2019 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, Volume 1 (Long and Short Papers), pages 3845–3856, Minneapolis, Minnesota. Association for Computational Linguistics.
Cite (Informal):
Low-Resource Syntactic Transfer with Unsupervised Source Reordering (Rasooli & Collins, NAACL 2019)
Copy Citation:
PDF:
https://aclanthology.org/N19-1385.pdf