F1 is Not Enough! Models and Evaluation Towards User-Centered Explainable Question Answering

Hendrik Schuff, Heike Adel, Ngoc Thang Vu


Abstract
Explainable question answering systems predict an answer together with an explanation showing why the answer has been selected. The goal is to enable users to assess the correctness of the system and understand its reasoning process. However, we show that current models and evaluation settings have shortcomings regarding the coupling of answer and explanation which might cause serious issues in user experience. As a remedy, we propose a hierarchical model and a new regularization term to strengthen the answer-explanation coupling as well as two evaluation scores to quantify the coupling. We conduct experiments on the HOTPOTQA benchmark data set and perform a user study. The user study shows that our models increase the ability of the users to judge the correctness of the system and that scores like F1 are not enough to estimate the usefulness of a model in a practical setting with human users. Our scores are better aligned with user experience, making them promising candidates for model selection.
Anthology ID:
2020.emnlp-main.575
Volume:
Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing (EMNLP)
Month:
November
Year:
2020
Address:
Online
Venue:
EMNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
7076–7095
Language:
URL:
https://aclanthology.org/2020.emnlp-main.575
DOI:
10.18653/v1/2020.emnlp-main.575
Bibkey:
Cite (ACL):
Hendrik Schuff, Heike Adel, and Ngoc Thang Vu. 2020. F1 is Not Enough! Models and Evaluation Towards User-Centered Explainable Question Answering. In Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing (EMNLP), pages 7076–7095, Online. Association for Computational Linguistics.
Cite (Informal):
F1 is Not Enough! Models and Evaluation Towards User-Centered Explainable Question Answering (Schuff et al., EMNLP 2020)
Copy Citation:
PDF:
https://aclanthology.org/2020.emnlp-main.575.pdf
Video:
 https://slideslive.com/38938814
Code
 boschresearch/f1-is-not-enough