TIARA: Multi-grained Retrieval for Robust Question Answering over Large Knowledge Base

Yiheng Shu, Zhiwei Yu, Yuhan Li, Börje Karlsson, Tingting Ma, Yuzhong Qu, Chin-Yew Lin


Abstract
Pre-trained language models (PLMs) have shown their effectiveness in multiple scenarios. However, KBQA remains challenging, especially regarding coverage and generalization settings. This is due to two main factors: i) understanding the semantics of both questions and relevant knowledge from the KB; ii) generating executable logical forms with both semantic and syntactic correctness. In this paper, we present a new KBQA model, TIARA, which addresses those issues by applying multi-grained retrieval to help the PLM focus on the most relevant KB context, viz., entities, exemplary logical forms, and schema items. Moreover, constrained decoding is used to control the output space and reduce generation errors. Experiments over important benchmarks demonstrate the effectiveness of our approach. TIARA outperforms previous SOTA, including those using PLMs or oracle entity annotations, by at least 4.1 and 1.1 F1 points on GrailQA and WebQuestionsSP, respectively. Specifically on GrailQA, TIARA outperforms previous models in all categories, with an improvement of 4.7 F1 points in zero-shot generalization.
Anthology ID:
2022.emnlp-main.555
Volume:
Proceedings of the 2022 Conference on Empirical Methods in Natural Language Processing
Month:
December
Year:
2022
Address:
Abu Dhabi, United Arab Emirates
Editors:
Yoav Goldberg, Zornitsa Kozareva, Yue Zhang
Venue:
EMNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
8108–8121
Language:
URL:
https://aclanthology.org/2022.emnlp-main.555
DOI:
10.18653/v1/2022.emnlp-main.555
Bibkey:
Cite (ACL):
Yiheng Shu, Zhiwei Yu, Yuhan Li, Börje Karlsson, Tingting Ma, Yuzhong Qu, and Chin-Yew Lin. 2022. TIARA: Multi-grained Retrieval for Robust Question Answering over Large Knowledge Base. In Proceedings of the 2022 Conference on Empirical Methods in Natural Language Processing, pages 8108–8121, Abu Dhabi, United Arab Emirates. Association for Computational Linguistics.
Cite (Informal):
TIARA: Multi-grained Retrieval for Robust Question Answering over Large Knowledge Base (Shu et al., EMNLP 2022)
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PDF:
https://aclanthology.org/2022.emnlp-main.555.pdf