Hierarchical Evidence Set Modeling for Automated Fact Extraction and Verification

Shyam Subramanian, Kyumin Lee


Abstract
Automated fact extraction and verification is a challenging task that involves finding relevant evidence sentences from a reliable corpus to verify the truthfulness of a claim. Existing models either (i) concatenate all the evidence sentences, leading to the inclusion of redundant and noisy information; or (ii) process each claim-evidence sentence pair separately and aggregate all of them later, missing the early combination of related sentences for more accurate claim verification. Unlike the prior works, in this paper, we propose Hierarchical Evidence Set Modeling (HESM), a framework to extract evidence sets (each of which may contain multiple evidence sentences), and verify a claim to be supported, refuted or not enough info, by encoding and attending the claim and evidence sets at different levels of hierarchy. Our experimental results show that HESM outperforms 7 state-of-the-art methods for fact extraction and claim verification. Our source code is available at https://github.com/ShyamSubramanian/HESM.
Anthology ID:
2020.emnlp-main.627
Volume:
Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing (EMNLP)
Month:
November
Year:
2020
Address:
Online
Editors:
Bonnie Webber, Trevor Cohn, Yulan He, Yang Liu
Venue:
EMNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
7798–7809
Language:
URL:
https://aclanthology.org/2020.emnlp-main.627
DOI:
10.18653/v1/2020.emnlp-main.627
Bibkey:
Cite (ACL):
Shyam Subramanian and Kyumin Lee. 2020. Hierarchical Evidence Set Modeling for Automated Fact Extraction and Verification. In Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing (EMNLP), pages 7798–7809, Online. Association for Computational Linguistics.
Cite (Informal):
Hierarchical Evidence Set Modeling for Automated Fact Extraction and Verification (Subramanian & Lee, EMNLP 2020)
Copy Citation:
PDF:
https://aclanthology.org/2020.emnlp-main.627.pdf
Video:
 https://slideslive.com/38939144
Code
 ShyamSubramanian/HESM
Data
FEVER