Relative Preference Optimization: Enhancing LLM Alignment through Contrasting Responses across Identical and Diverse Prompts

26 Sept 2024 (modified: 05 Feb 2025)Submitted to ICLR 2025EveryoneRevisionsBibTeXCC BY 4.0
Keywords: LLM alignment, fine-tuning, preferences
TL;DR: Relative Preference Optimization (RPO) utilizes a contrastive weighting mechanism to better align Large Language Models with user preferences by learning from both identical and related prompts, demonstrating enhanced performance in various tests.
Abstract: In the field of large language models (LLMs), aligning models with the diverse preferences of users is a critical challenge. Direct Preference Optimization (DPO) has played a key role in this area. It works by using pairs of preferences derived from the same prompts, and it functions without needing an additional reward model. However, DPO does not fully reflect the complex nature of human learning, which often involves understanding contrasting responses to not only identical but also similar questions. To overcome this shortfall, we propose Relative Preference Optimization (RPO). RPO is designed to discern between more and less preferred responses derived from both identical and related prompts. It introduces a contrastive weighting mechanism, enabling the tuning of LLMs using a broader range of preference data, including both paired and unpaired sets. This approach expands the learning capabilities of the model, allowing it to leverage insights from a more varied set of prompts. Experiments in both paired and unpaired dataset settings, including tasks like dialogue, summarization, and general evaluation benchmarks, demonstrate RPO's superior ability to align LLMs with user preferences and enhance adaptability during training.
Primary Area: alignment, fairness, safety, privacy, and societal considerations
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Submission Number: 8305
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