Long-Tailed Question Answering in an Open World

Yi Dai, Hao Lang, Yinhe Zheng, Fei Huang, Yongbin Li


Abstract
Real-world data often have an open long-tailed distribution, and building a unified QA model supporting various tasks is vital for practical QA applications. However, it is non-trivial to extend previous QA approaches since they either require access to seen tasks of adequate samples or do not explicitly model samples from unseen tasks. In this paper, we define Open Long-Tailed QA (OLTQA) as learning from long-tailed distributed data and optimizing performance over seen and unseen QA tasks. We propose an OLTQA model that encourages knowledge sharing between head, tail and unseen tasks, and explicitly mines knowledge from a large pre-trained language model (LM).Specifically, we organize our model through a pool of fine-grained components and dynamically combine these components for an input to facilitate knowledge sharing.A retrieve-then-rerank frame is further introduced to select in-context examples, which guild the LM to generate text that express knowledge for QA tasks. Moreover, a two-stage training approach is introduced to pre-train the framework by knowledge distillation (KD) from the LM and then jointly train the frame and a QA model through an adaptive mutual KD method. On a large-scale OLTQA dataset we curate from 43 existing QA datasets, our model consistently outperforms the state-of-the-art.
Anthology ID:
2023.acl-long.351
Volume:
Proceedings of the 61st Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
July
Year:
2023
Address:
Toronto, Canada
Editors:
Anna Rogers, Jordan Boyd-Graber, Naoaki Okazaki
Venue:
ACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
6362–6382
Language:
URL:
https://aclanthology.org/2023.acl-long.351
DOI:
10.18653/v1/2023.acl-long.351
Bibkey:
Cite (ACL):
Yi Dai, Hao Lang, Yinhe Zheng, Fei Huang, and Yongbin Li. 2023. Long-Tailed Question Answering in an Open World. In Proceedings of the 61st Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 6362–6382, Toronto, Canada. Association for Computational Linguistics.
Cite (Informal):
Long-Tailed Question Answering in an Open World (Dai et al., ACL 2023)
Copy Citation:
PDF:
https://aclanthology.org/2023.acl-long.351.pdf
Video:
 https://aclanthology.org/2023.acl-long.351.mp4