CORAL: Adaptive Retrieval Loop for Culturally-Aligned Multilingual RAG

Nayeon Lee, Jiwoo Song, Byeongcheol Kang


Abstract
Multilingual retrieval-augmented generation (mRAG) is often implemented within a fixed retrieval space, typically via query or document translation or multilingual embedding vector representations. However, this approach may be inadequate for culturally grounded queries, in which retrieval-condition misalignment may occur. Even strong retrievers and generators may struggle to produce culturally relevant answers when sourcing evidence from inappropriate linguistic or regional contexts. To this end, we introduce CORAL (COntext-aware Retrieval with Agentic Loop, an adaptive retrieval methodology for mRAG that enables iterative refinement of both the retrieval space (corpora) and the retrieval probe (query) based on the quality of the evidence. The overall process includes: (1) selecting corpora, (2) retrieving documents, (3) critiquing evidence for relevance and cultural alignment, and (4) checking sufficiency. If the retrieved documents are insufficient to answer the query correctly, the system (5) reselects corpora and rewrites the query. Across two cultural QA benchmarks, CORAL achieves up to a 3.58%p accuracy improvement on low-resource languages relative to the strongest baselines.
Anthology ID:
2026.findings-acl.1356
Volume:
Findings of the Association for Computational Linguistics: ACL 2026
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
Findings
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Publisher:
Association for Computational Linguistics
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Pages:
27215–27237
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URL:
https://preview.aclanthology.org/ingest-acl-workshops/2026.findings-acl.1356/
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Cite (ACL):
Nayeon Lee, Jiwoo Song, and Byeongcheol Kang. 2026. CORAL: Adaptive Retrieval Loop for Culturally-Aligned Multilingual RAG. In Findings of the Association for Computational Linguistics: ACL 2026, pages 27215–27237, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
CORAL: Adaptive Retrieval Loop for Culturally-Aligned Multilingual RAG (Lee et al., Findings 2026)
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https://preview.aclanthology.org/ingest-acl-workshops/2026.findings-acl.1356.pdf
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