Syntax and Geometry of Information

Raphaël Bailly, Laurent Leblond, Kata Gábor


Abstract
This paper presents an information-theoretical model of syntactic generalization. We study syntactic generalization from the perspective of the capacity to disentangle semantic and structural information, emulating the human capacity to assign a grammaticality judgment to semantically nonsensical sentences. In order to isolate the structure, we propose to represent the probability distribution behind a corpus as the product of the probability of a semantic context and the probability of a structure, the latter being independent of the former. We further elaborate the notion of abstraction as a relaxation of the property of independence. It is based on the measure of structural and contextual information for a given representation. We test abstraction as an optimization objective on the task of inducing syntactic categories from natural language data and show that it significantly outperforms alternative methods. Furthermore, we find that when syntax-unaware optimization objectives succeed in the task, their success is mainly due to an implicit disentanglement process rather than to the model structure. On the other hand, syntactic categories can be deduced in a principled way from the independence between structure and context.
Anthology ID:
2023.acl-long.590
Volume:
Proceedings of the 61st Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
July
Year:
2023
Address:
Toronto, Canada
Editors:
Anna Rogers, Jordan Boyd-Graber, Naoaki Okazaki
Venue:
ACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
10576–10595
Language:
URL:
https://aclanthology.org/2023.acl-long.590
DOI:
10.18653/v1/2023.acl-long.590
Bibkey:
Cite (ACL):
Raphaël Bailly, Laurent Leblond, and Kata Gábor. 2023. Syntax and Geometry of Information. In Proceedings of the 61st Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 10576–10595, Toronto, Canada. Association for Computational Linguistics.
Cite (Informal):
Syntax and Geometry of Information (Bailly et al., ACL 2023)
Copy Citation:
PDF:
https://aclanthology.org/2023.acl-long.590.pdf
Video:
 https://aclanthology.org/2023.acl-long.590.mp4