Pre-training Language Models with Deterministic Factual Knowledge

Shaobo Li, Xiaoguang Li, Lifeng Shang, Chengjie Sun, Bingquan Liu, Zhenzhou Ji, Xin Jiang, Qun Liu


Abstract
Previous works show that Pre-trained Language Models (PLMs) can capture factual knowledge. However, some analyses reveal that PLMs fail to perform it robustly, e.g., being sensitive to the changes of prompts when extracting factual knowledge. To mitigate this issue, we propose to let PLMs learn the deterministic relationship between the remaining context and the masked content. The deterministic relationship ensures that the masked factual content can be deterministically inferable based on the existing clues in the context. That would provide more stable patterns for PLMs to capture factual knowledge than randomly masking. Two pre-training tasks are further introduced to motivate PLMs to rely on the deterministic relationship when filling masks. Specifically, we use an external Knowledge Base (KB) to identify deterministic relationships and continuously pre-train PLMs with the proposed methods. The factual knowledge probing experiments indicate that the continuously pre-trained PLMs achieve better robustness in factual knowledge capturing. Further experiments on question-answering datasets show that trying to learn a deterministic relationship with the proposed methods can also help other knowledge-intensive tasks.
Anthology ID:
2022.emnlp-main.764
Volume:
Proceedings of the 2022 Conference on Empirical Methods in Natural Language Processing
Month:
December
Year:
2022
Address:
Abu Dhabi, United Arab Emirates
Editors:
Yoav Goldberg, Zornitsa Kozareva, Yue Zhang
Venue:
EMNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
11118–11131
Language:
URL:
https://aclanthology.org/2022.emnlp-main.764
DOI:
10.18653/v1/2022.emnlp-main.764
Bibkey:
Cite (ACL):
Shaobo Li, Xiaoguang Li, Lifeng Shang, Chengjie Sun, Bingquan Liu, Zhenzhou Ji, Xin Jiang, and Qun Liu. 2022. Pre-training Language Models with Deterministic Factual Knowledge. In Proceedings of the 2022 Conference on Empirical Methods in Natural Language Processing, pages 11118–11131, Abu Dhabi, United Arab Emirates. Association for Computational Linguistics.
Cite (Informal):
Pre-training Language Models with Deterministic Factual Knowledge (Li et al., EMNLP 2022)
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PDF:
https://aclanthology.org/2022.emnlp-main.764.pdf