TACR: A Table Alignment-based Cell Selection Method for HybridQA

Jian Wu, Yicheng Xu, Yan Gao, Jian-Guang Lou, Börje Karlsson, Manabu Okumura


Abstract
Hybrid Question-Answering (HQA), which targets reasoning over tables and passages linked from table cells, has witnessed significant research in recent years. A common challenge in HQA and other passage-table QA datasets is that it is generally unrealistic to iterate over all table rows, columns, and linked passages to retrieve evidence. Such a challenge made it difficult for previous studies to show their reasoning ability in retrieving answers. To bridge this gap, we propose a novel Table-alignment-based Cell-selection and Reasoning model (TACR) for hybrid text and table QA, evaluated on the HybridQA and WikiTableQuestions datasets. In evidence retrieval, we design a table-question-alignment enhanced cell-selection method to retrieve fine-grained evidence. In answer reasoning, we incorporate a QA module that treats the row containing selected cells as context. Experimental results over the HybridQA and WikiTableQuestions (WTQ) datasets show that TACR achieves state-of-the-art results on cell selection and outperforms fine-grained evidence retrieval baselines on HybridQA, while achieving competitive performance on WTQ. We also conducted a detailed analysis to demonstrate that being able to align questions to tables in the cell-selection stage can result in important gains from experiments of over 90% table row and column selection accuracy, meanwhile also improving output explainability.
Anthology ID:
2023.findings-acl.409
Volume:
Findings of the Association for Computational Linguistics: ACL 2023
Month:
July
Year:
2023
Address:
Toronto, Canada
Editors:
Anna Rogers, Jordan Boyd-Graber, Naoaki Okazaki
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
6535–6549
Language:
URL:
https://aclanthology.org/2023.findings-acl.409
DOI:
10.18653/v1/2023.findings-acl.409
Bibkey:
Cite (ACL):
Jian Wu, Yicheng Xu, Yan Gao, Jian-Guang Lou, Börje Karlsson, and Manabu Okumura. 2023. TACR: A Table Alignment-based Cell Selection Method for HybridQA. In Findings of the Association for Computational Linguistics: ACL 2023, pages 6535–6549, Toronto, Canada. Association for Computational Linguistics.
Cite (Informal):
TACR: A Table Alignment-based Cell Selection Method for HybridQA (Wu et al., Findings 2023)
Copy Citation:
PDF:
https://aclanthology.org/2023.findings-acl.409.pdf