MPPO: Multi Pair-wise Preference Optimization for LLMs with Arbitrary Negative Samples
This addresses the challenge of efficiently aligning LLMs with human preferences, particularly in multi-reply scenarios, though it appears incremental relative to existing preference optimization methods.
The paper tackles the problem of aligning large language models with human feedback by introducing MPPO, a preference optimization algorithm that maximizes utilization of preference data and outperforms existing methods like DPO and ORPO on benchmarks such as MT-Bench and Arena-Hard.
Aligning Large Language Models (LLMs) with human feedback is crucial for their development. Existing preference optimization methods such as DPO and KTO, while improved based on Reinforcement Learning from Human Feedback (RLHF), are inherently derived from PPO, requiring a reference model that adds GPU memory resources and relies heavily on abundant preference data. Meanwhile, current preference optimization research mainly targets single-question scenarios with two replies, neglecting optimization with multiple replies, which leads to a waste of data in the application. This study introduces the MPPO algorithm, which leverages the average likelihood of model responses to fit the reward function and maximizes the utilization of preference data. Through a comparison of Point-wise, Pair-wise, and List-wise implementations, we found that the Pair-wise approach achieves the best performance, significantly enhancing the quality of model responses. Experimental results demonstrate MPPO's outstanding performance across various benchmarks. On MT-Bench, MPPO outperforms DPO, ORPO, and SimPO. Notably, on Arena-Hard, MPPO surpasses DPO and ORPO by substantial margins. These achievements underscore the remarkable advantages of MPPO in preference optimization tasks.