Progressive Re-ranking for Multimodal Retrieval-Augmented Generation via Curriculum Learning

Zhu Min, Yanchao Hao, Jian Liu, Shizhu He, Xi Chen


Abstract
Retrieval-augmented generation (RAG) can enhance large language models (LLMs) by providing external knowledge and helping reduce hallucinations. In multimodal RAG, however, retrieval remains challenging because a single retriever may fail to capture fine-grained multimodal semantics, and visually or semantically similar entities may still contain misleading information for answer generation. We propose a progressive multimodal re-ranking framework with curriculum learning to improve CLIP-based visual coarse-grained retrieval. Our framework progressively refines retrieval results through two stages: fine-grained section-level re-ranking and multimodal section reassessment. To better align re-ranking with multimodal queries, we introduce a curriculum-learning strategy that trains the model with hard negatives that are visually or semantically similar but contain misleading information. Experiments on InfoSeek and Enc-VQA show that our method achieves state-of-the-art answer accuracy and competitive retrieval performance.
Anthology ID:
2026.findings-acl.2045
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:
41135–41147
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URL:
https://preview.aclanthology.org/ingest-acl/2026.findings-acl.2045/
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Cite (ACL):
Zhu Min, Yanchao Hao, Jian Liu, Shizhu He, and Xi Chen. 2026. Progressive Re-ranking for Multimodal Retrieval-Augmented Generation via Curriculum Learning. In Findings of the Association for Computational Linguistics: ACL 2026, pages 41135–41147, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
Progressive Re-ranking for Multimodal Retrieval-Augmented Generation via Curriculum Learning (Min et al., Findings 2026)
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https://preview.aclanthology.org/ingest-acl/2026.findings-acl.2045.pdf
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