UnIte: Uncertainty-based Iterative Document Sampling for Domain Adaptation in Information Retrieval

Jongyoon Kim, Minseong Hwang, Seung-won Hwang


Abstract
Unsupervised domain adaptation generalizes neural retrievers to an unseen domain by generating pseudo queries on target domain documents. The quality and efficiency of this adaptation critically depend on which documents are selected for pseudo query generation. The existing document sampling method focuses on diversity but fails to capture model uncertainty. In contrast, we propose Uncertainty-based Iterative Document Sampling (UnIte), addressing these limitations by (1) filtering documents with high aleatoric uncertainty and (2) prioritizing those with high epistemic uncertainty, maximizing the learning utility of the current model. We conducted extensive experiments on a large corpus of BEIR with small and large models, showing significant gains of +2.45 and +3.49 nDCG@10 with a smaller training sample size, 4k on average.
Anthology ID:
2026.findings-acl.1614
Volume:
Findings of the Association for Computational Linguistics: ACL 2026
Month:
July
Year:
2026
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San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
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Findings
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Publisher:
Association for Computational Linguistics
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Pages:
32256–32272
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https://preview.aclanthology.org/ingest-acl/2026.findings-acl.1614/
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Cite (ACL):
Jongyoon Kim, Minseong Hwang, and Seung-won Hwang. 2026. UnIte: Uncertainty-based Iterative Document Sampling for Domain Adaptation in Information Retrieval. In Findings of the Association for Computational Linguistics: ACL 2026, pages 32256–32272, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
UnIte: Uncertainty-based Iterative Document Sampling for Domain Adaptation in Information Retrieval (Kim et al., Findings 2026)
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https://preview.aclanthology.org/ingest-acl/2026.findings-acl.1614.pdf
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