Unsupervised Dependency Graph Network

Yikang Shen, Shawn Tan, Alessandro Sordoni, Peng Li, Jie Zhou, Aaron Courville


Abstract
Recent work has identified properties of pretrained self-attention models that mirror those of dependency parse structures. In particular, some self-attention heads correspond well to individual dependency types. Inspired by these developments, we propose a new competitive mechanism that encourages these attention heads to model different dependency relations. We introduce a new model, the Unsupervised Dependency Graph Network (UDGN), that can induce dependency structures from raw corpora and the masked language modeling task. Experiment results show that UDGN achieves very strong unsupervised dependency parsing performance without gold POS tags and any other external information. The competitive gated heads show a strong correlation with human-annotated dependency types. Furthermore, the UDGN can also achieve competitive performance on masked language modeling and sentence textual similarity tasks.
Anthology ID:
2022.acl-long.327
Volume:
Proceedings of the 60th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
May
Year:
2022
Address:
Dublin, Ireland
Editors:
Smaranda Muresan, Preslav Nakov, Aline Villavicencio
Venue:
ACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
4767–4784
Language:
URL:
https://aclanthology.org/2022.acl-long.327
DOI:
10.18653/v1/2022.acl-long.327
Bibkey:
Cite (ACL):
Yikang Shen, Shawn Tan, Alessandro Sordoni, Peng Li, Jie Zhou, and Aaron Courville. 2022. Unsupervised Dependency Graph Network. In Proceedings of the 60th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 4767–4784, Dublin, Ireland. Association for Computational Linguistics.
Cite (Informal):
Unsupervised Dependency Graph Network (Shen et al., ACL 2022)
Copy Citation:
PDF:
https://aclanthology.org/2022.acl-long.327.pdf
Video:
 https://aclanthology.org/2022.acl-long.327.mp4
Code
 yikangshen/udgn
Data
Penn Treebank