SARA: Salience-Aware Reinforced Adaptive Decoding for Large Language Models in Abstractive Summarization

Nayu Liu, Junnan Zhu, Yiming Ma, Zhicong Lu, Wenlei Xu, Yong Yang, Jiang Zhong, Kaiwen Wei


Abstract
LLMs have improved the fluency and informativeness of abstractive summarization but remain prone to hallucinations, where generated content deviates from the source document. Recent PMI decoding strategies mitigate over-reliance on prior knowledge by comparing output probabilities with and without source documents, effectively enhancing contextual utilization and improving faithfulness. However, existing strategies often neglect the explicit use of salient contextual information and rely on static hyperparameters to fix the balance between contextual and prior knowledge, limiting their flexibility. In this work, we propose Salience-Aware Reinforced Adaptive decoding (SARA), which incorporates salient information and allows the model to adaptively determine reliance on the source document’s context, salient context, and the model’s prior knowledge based on pointwise mutual information. Moreover, a tokenwise adaptive decoding mechanism via reinforcement learning is proposed in SARA to dynamically adjust the contributions of context and prior knowledge at each decoding timestep. Experiments on CNN/DM, WikiHow, and NYT50 datasets show that SARA consistently improves the quality and faithfulness of summaries across various LLM backbones without modifying their weights.
Anthology ID:
2025.acl-long.1236
Volume:
Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
July
Year:
2025
Address:
Vienna, Austria
Editors:
Wanxiang Che, Joyce Nabende, Ekaterina Shutova, Mohammad Taher Pilehvar
Venue:
ACL
SIG:
Publisher:
Association for Computational Linguistics
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Pages:
25450–25463
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URL:
https://preview.aclanthology.org/ingestion-acl-25/2025.acl-long.1236/
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Bibkey:
Cite (ACL):
Nayu Liu, Junnan Zhu, Yiming Ma, Zhicong Lu, Wenlei Xu, Yong Yang, Jiang Zhong, and Kaiwen Wei. 2025. SARA: Salience-Aware Reinforced Adaptive Decoding for Large Language Models in Abstractive Summarization. In Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 25450–25463, Vienna, Austria. Association for Computational Linguistics.
Cite (Informal):
SARA: Salience-Aware Reinforced Adaptive Decoding for Large Language Models in Abstractive Summarization (Liu et al., ACL 2025)
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https://preview.aclanthology.org/ingestion-acl-25/2025.acl-long.1236.pdf