Trust the Context, Not the Weights: Faithful Multi-Hop QA via Synthetic Mid-Training

Maksim Savkin, Mikhail Goncharov, Alexander Gambashidze, Alla Chepurova, Dmitrii Tarasov, Timur Ionov, Nikita Andriianov, Daria Pugacheva, Ivan Oseledets, Vasily Konovalov, Andrey V. Galichin


Abstract
Recent progress in language models has been defined by scale, yet many practical applications benefit more from robust reasoning than extensive parametric knowledge. We introduce OCC-RAG, a family of models for faithful context-based QA, which prioritizes task-specific reasoning capabilities over knowledge capacity. To train OCC-RAG, we implement a novel pipeline synthesizing over three million multi-context, multi-hop QA examples that target multi-hop reasoning, strict context faithfulness, and calibrated abstention. Mid-trained on this corpus, the models produce structured reasoning traces with source citations grounded in literal quotes from the context. Despite their compact size, OCC-RAG models outperform their same-size general-purpose counterparts on every benchmark and exceed models 2–6× larger on financial reasoning (TAT-QA) and faithfulness (ConFiQA), attaining the best results among all evaluated open-weight models up to 32B parameters. On ConFiQA they rank behind only a frontier proprietary models; on multi-hop reasoning (HotpotQA, MuSiQue) and refusal (MuSiQue-Un) they are on par with 8B-class models and close much of the remaining gap to the largest evaluated systems. We release both our code and family of models.[<https://hf.co/collections/occ-ai/occ-rag>]
Anthology ID:
2026.emnlp-demos.47
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing: System Demonstrations
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Sweta Agrawal, Alberto Abad
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
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Pages:
488–497
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URL:
https://aclanthology.org/2026.emnlp-demos.47/
DOI:
Bibkey:
Cite (ACL):
Maksim Savkin, Mikhail Goncharov, Alexander Gambashidze, Alla Chepurova, Dmitrii Tarasov, Timur Ionov, Nikita Andriianov, Daria Pugacheva, Ivan Oseledets, Vasily Konovalov, and Andrey V. Galichin. 2026. Trust the Context, Not the Weights: Faithful Multi-Hop QA via Synthetic Mid-Training. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing: System Demonstrations, pages 488–497, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Trust the Context, Not the Weights: Faithful Multi-Hop QA via Synthetic Mid-Training (Savkin et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-demos.47.pdf