Abstract
We propose a new method for projective dependency parsing based on headed spans. In a projective dependency tree, the largest subtree rooted at each word covers a contiguous sequence (i.e., a span) in the surface order. We call such a span marked by a root word headed span. A projective dependency tree can be represented as a collection of headed spans. We decompose the score of a dependency tree into the scores of the headed spans and design a novel O(n3) dynamic programming algorithm to enable global training and exact inference. Our model achieves state-of-the-art or competitive results on PTB, CTB, and UD- Anthology ID:
- 2022.acl-long.155
- 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:
- 2188–2200
- Language:
- URL:
- https://aclanthology.org/2022.acl-long.155
- DOI:
- 10.18653/v1/2022.acl-long.155
- Cite (ACL):
- Songlin Yang and Kewei Tu. 2022. Headed-Span-Based Projective Dependency Parsing. In Proceedings of the 60th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 2188–2200, Dublin, Ireland. Association for Computational Linguistics.
- Cite (Informal):
- Headed-Span-Based Projective Dependency Parsing (Yang & Tu, ACL 2022)
- PDF:
- https://preview.aclanthology.org/nschneid-patch-3/2022.acl-long.155.pdf
- Code
- sustcsonglin/span-based-dependency-parsing