Iterative Repair with Weak Verifiers for Few-shot Transfer in KBQA with Unanswerability

Riya Sawhney, Samrat Yadav, Indrajit Bhattacharya, Mausam Mausam


Abstract
Real-world applications of KBQA require models to detect different types of unanswerable questions with a limited volume of in-domain labeled training data. We propose the novel task of few-shot transfer for KBQA with unanswerable questions. The state-of-the-art KBQA few-shot transfer model (FuSIC-KBQA) uses an iterative repair strategy that assumes that all questions are answerable. As a remedy, we present FUn-FuSIC – a novel solution for our task that extends FuSIC-KBQA with Feedback for Unanswerability (FUn), which is an iterative repair strategy for answerable as well as unanswerable questions. FUn uses feedback from a suite of strong and weak verifiers, and an adaptation of self-consistency for unanswerability for assessing answerability of questions. Our experiments show that FUn-FuSIC significantly outperforms suitable adaptations of multiple LLM-based and supervised SoTA models on our task, while establishing a new SoTA performance for answerable few-shot transfer as well. We have made datasets and other resources publicly available at https://github.com/dair-iitd/funfusic/.
Anthology ID:
2025.findings-acl.1262
Volume:
Findings of the Association for Computational Linguistics: ACL 2025
Month:
July
Year:
2025
Address:
Vienna, Austria
Editors:
Wanxiang Che, Joyce Nabende, Ekaterina Shutova, Mohammad Taher Pilehvar
Venue:
Findings
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Publisher:
Association for Computational Linguistics
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Pages:
24578–24596
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URL:
https://preview.aclanthology.org/landing_page/2025.findings-acl.1262/
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Cite (ACL):
Riya Sawhney, Samrat Yadav, Indrajit Bhattacharya, and Mausam Mausam. 2025. Iterative Repair with Weak Verifiers for Few-shot Transfer in KBQA with Unanswerability. In Findings of the Association for Computational Linguistics: ACL 2025, pages 24578–24596, Vienna, Austria. Association for Computational Linguistics.
Cite (Informal):
Iterative Repair with Weak Verifiers for Few-shot Transfer in KBQA with Unanswerability (Sawhney et al., Findings 2025)
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https://preview.aclanthology.org/landing_page/2025.findings-acl.1262.pdf