Learning Knowledge-Enhanced Contextual Language Representations for Domain Natural Language Understanding

Taolin Zhang, Ruyao Xu, Chengyu Wang, Zhongjie Duan, Cen Chen, Minghui Qiu, Dawei Cheng, Xiaofeng He, Weining Qian


Abstract
Knowledge-Enhanced Pre-trained Language Models (KEPLMs) improve the performance of various downstream NLP tasks by injecting knowledge facts from large-scale Knowledge Graphs (KGs). However, existing methods for pre-training KEPLMs with relational triples are difficult to be adapted to close domains due to the lack of sufficient domain graph semantics. In this paper, we propose a Knowledge-enhanced language representation learning framework for various closed domains (KANGAROO) via capturing the implicit graph structure among the entities. Specifically, since the entity coverage rates of closed-domain KGs can be relatively low and may exhibit the global sparsity phenomenon for knowledge injection, we consider not only the shallow relational representations of triples but also the hyperbolic embeddings of deep hierarchical entity-class structures for effective knowledge fusion. Moreover, as two closed-domain entities under the same entity-class often havel locally dense neighbor subgraphs counted by max point biconnected component, we further propose a data augmentation strategy based on contrastive learning over subgraphs to construct hard negative samples of higher quality. It makes the underlying KELPMs better distinguish the semantics of these neighboring entities to further complement the global semantic sparsity. In the experiments, we evaluate KANGAROO over various knowledge-aware and general NLP tasks in both full and few-shot learning settings, outperforming various KEPLM training paradigms performance in closed-domains significantly.
Anthology ID:
2023.emnlp-main.969
Volume:
Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing
Month:
December
Year:
2023
Address:
Singapore
Editors:
Houda Bouamor, Juan Pino, Kalika Bali
Venue:
EMNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
15663–15676
Language:
URL:
https://aclanthology.org/2023.emnlp-main.969
DOI:
10.18653/v1/2023.emnlp-main.969
Bibkey:
Cite (ACL):
Taolin Zhang, Ruyao Xu, Chengyu Wang, Zhongjie Duan, Cen Chen, Minghui Qiu, Dawei Cheng, Xiaofeng He, and Weining Qian. 2023. Learning Knowledge-Enhanced Contextual Language Representations for Domain Natural Language Understanding. In Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing, pages 15663–15676, Singapore. Association for Computational Linguistics.
Cite (Informal):
Learning Knowledge-Enhanced Contextual Language Representations for Domain Natural Language Understanding (Zhang et al., EMNLP 2023)
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PDF:
https://aclanthology.org/2023.emnlp-main.969.pdf
Video:
 https://aclanthology.org/2023.emnlp-main.969.mp4