🤖 AI Summary
Existing preference datasets lack explicit modeling of human decision rationales, resulting in inefficient alignment learning, susceptibility to redundant expressions and hallucinations, and prohibitively high annotation costs. This paper proposes a data-centric rationale-augmented paradigm: (1) it is the first to systematically validate the efficacy of free large language models (LLMs) for self-generating decision rationales in preference learning; (2) it introduces a lightweight, general-purpose rationale injection framework that requires no additional human annotation or model fine-tuning and is compatible with mainstream algorithms such as DPO and KTO; and (3) it jointly optimizes rationale-guided contrastive learning and supervised fine-tuning. Experiments demonstrate substantial improvements in data efficiency and training convergence speed, consistent reductions in hallucination rates and redundant outputs across multiple benchmarks, and state-of-the-art performance gains.
📝 Abstract
Reinforcement learning from human feedback plays a crucial role in aligning language models towards human preferences, traditionally represented through comparisons between pairs or sets of responses within a given context. While many studies have enhanced algorithmic techniques to optimize learning from such data, this work shifts focus to improving preference learning through a data-centric approach. Specifically, we propose enriching existing preference datasets with machine-generated rationales that explain the reasons behind choices. We develop a simple and principled framework to augment current preference learning methods with rationale information. Our comprehensive analysis highlights how rationales enhance learning efficiency. Extensive experiments reveal that rationale-enriched preference learning offers multiple advantages: it improves data efficiency, accelerates convergence to higher-performing models, and reduces verbosity bias and hallucination. Furthermore, this framework is versatile enough to integrate with various preference optimization algorithms. Overall, our findings highlight the potential of re-imagining data design for preference learning, demonstrating that even freely available machine-generated rationales can significantly boost performance across multiple dimensions. The code repository is available at https: //github.com/reds-lab/preference-learning-with-rationales