Robustifying Multi-hop QA through Pseudo-Evidentiality Training

Kyungjae Lee, Seung-won Hwang, Sang-eun Han, Dohyeon Lee


Abstract
This paper studies the bias problem of multi-hop question answering models, of answering correctly without correct reasoning. One way to robustify these models is by supervising to not only answer right, but also with right reasoning chains. An existing direction is to annotate reasoning chains to train models, requiring expensive additional annotations. In contrast, we propose a new approach to learn evidentiality, deciding whether the answer prediction is supported by correct evidences, without such annotations. Instead, we compare counterfactual changes in answer confidence with and without evidence sentences, to generate “pseudo-evidentiality” annotations. We validate our proposed model on an original set and challenge set in HotpotQA, showing that our method is accurate and robust in multi-hop reasoning.
Anthology ID:
2021.acl-long.476
Volume:
Proceedings of the 59th Annual Meeting of the Association for Computational Linguistics and the 11th International Joint Conference on Natural Language Processing (Volume 1: Long Papers)
Month:
August
Year:
2021
Address:
Online
Editors:
Chengqing Zong, Fei Xia, Wenjie Li, Roberto Navigli
Venues:
ACL | IJCNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
6110–6119
Language:
URL:
https://aclanthology.org/2021.acl-long.476
DOI:
10.18653/v1/2021.acl-long.476
Bibkey:
Cite (ACL):
Kyungjae Lee, Seung-won Hwang, Sang-eun Han, and Dohyeon Lee. 2021. Robustifying Multi-hop QA through Pseudo-Evidentiality Training. In Proceedings of the 59th Annual Meeting of the Association for Computational Linguistics and the 11th International Joint Conference on Natural Language Processing (Volume 1: Long Papers), pages 6110–6119, Online. Association for Computational Linguistics.
Cite (Informal):
Robustifying Multi-hop QA through Pseudo-Evidentiality Training (Lee et al., ACL-IJCNLP 2021)
Copy Citation:
PDF:
https://aclanthology.org/2021.acl-long.476.pdf
Video:
 https://aclanthology.org/2021.acl-long.476.mp4
Data
HotpotQA