Beyond Online Sampling: Bridging Offline-to-Online Alignment via Dynamic Data Transformation for LLMs

Zhang Zhang, Guhao Feng, Jian Guan, Di He, Wei Wu


Abstract
While Direct Preference Optimization (DPO) eliminates complex reward modeling in aligning large language models (LLMs) with human preferences, its online variant faces significant efficiency bottlenecks due to costly real-time preference sampling and the reward model annotation. We propose a novel framework that bridges offline-to-online alignment by systematically transforming static datasets into dynamically adaptive equivalents, without the need for an explicit reward model. Our approach employs paraphrasing techniques to preserve response correctness while aligning data distributions with model-generated outputs, circumventing the need for resource-intensive online interactions. Experiments on mathematical reasoning and conversational tasks demonstrate that our method matches or exceeds the performance of a fully online DPO. This work establishes a computationally sustainable paradigm for LLM alignment, particularly benefiting scenarios requiring iterative preference updates and domain adaptation.
Anthology ID:
2025.emnlp-main.1378
Volume:
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing
Month:
November
Year:
2025
Address:
Suzhou, China
Editors:
Christos Christodoulopoulos, Tanmoy Chakraborty, Carolyn Rose, Violet Peng
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EMNLP
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Publisher:
Association for Computational Linguistics
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Pages:
27085–27097
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https://preview.aclanthology.org/ingest-emnlp/2025.emnlp-main.1378/
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Cite (ACL):
Zhang Zhang, Guhao Feng, Jian Guan, Di He, and Wei Wu. 2025. Beyond Online Sampling: Bridging Offline-to-Online Alignment via Dynamic Data Transformation for LLMs. In Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing, pages 27085–27097, Suzhou, China. Association for Computational Linguistics.
Cite (Informal):
Beyond Online Sampling: Bridging Offline-to-Online Alignment via Dynamic Data Transformation for LLMs (Zhang et al., EMNLP 2025)
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