Understanding Dataset Design Choices for Multi-hop Reasoning

Jifan Chen, Greg Durrett


Abstract
Learning multi-hop reasoning has been a key challenge for reading comprehension models, leading to the design of datasets that explicitly focus on it. Ideally, a model should not be able to perform well on a multi-hop question answering task without doing multi-hop reasoning. In this paper, we investigate two recently proposed datasets, WikiHop and HotpotQA. First, we explore sentence-factored models for these tasks; by design, these models cannot do multi-hop reasoning, but they are still able to solve a large number of examples in both datasets. Furthermore, we find spurious correlations in the unmasked version of WikiHop, which make it easy to achieve high performance considering only the questions and answers. Finally, we investigate one key difference between these datasets, namely span-based vs. multiple-choice formulations of the QA task. Multiple-choice versions of both datasets can be easily gamed, and two models we examine only marginally exceed a baseline in this setting. Overall, while these datasets are useful testbeds, high-performing models may not be learning as much multi-hop reasoning as previously thought.
Anthology ID:
N19-1405
Volume:
Proceedings of the 2019 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, Volume 1 (Long and Short Papers)
Month:
June
Year:
2019
Address:
Minneapolis, Minnesota
Venue:
NAACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
4026–4032
Language:
URL:
https://aclanthology.org/N19-1405
DOI:
10.18653/v1/N19-1405
Bibkey:
Cite (ACL):
Jifan Chen and Greg Durrett. 2019. Understanding Dataset Design Choices for Multi-hop Reasoning. In Proceedings of the 2019 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, Volume 1 (Long and Short Papers), pages 4026–4032, Minneapolis, Minnesota. Association for Computational Linguistics.
Cite (Informal):
Understanding Dataset Design Choices for Multi-hop Reasoning (Chen & Durrett, NAACL 2019)
Copy Citation:
PDF:
https://preview.aclanthology.org/update-css-js/N19-1405.pdf
Video:
 https://vimeo.com/361800281
Data
HotpotQASQuADWikiHop