Supervised Fine-Tuning (SFT) on human demonstrations combined with Reinforcement Learning from Human Feedback (RLHF) constitutes a powerful alignment paradigm for Large Language Model (LLM) AI-assistant agents. However, a significant limitation of this approach is its substantial dependency on high-quality human annotations, making its broader application to intricate tasks challenging due to difficulties in obtaining consistent response demonstrations and task-specific response preferences. To address this issue, we present a novel alignment paradigm in this paper, termed SALMON (Self-ALignMent with principle-fOllowiNg reward models). This paradigm offers the ability to align base language models with minimal human supervision, using only a select set of human-defined principles, yet achieves superior performance. Central to our approach is a principle-following reward model. Trained on synthetic preference data, this reward model can generate reward scores based on arbitrary human-defined principles. Therefore, during the RL training phase, by merely adjusting these principles, we gain full control over the preferences of the reward model, subsequently influencing the behavior of the RL-trained policy model, and eliminating the traditional reliance on exhaustive online human preference collection. Applying our method to the LLaMA-2-70b base language model, we developed an AI assistant named Dromedary-2. With only 6 exemplars for in-context learning and 31 human-defined principles, Dromedary-2 significantly surpasses the performance of several state-of-the-art AI systems, including LLaMA-2-Chat-70b, on various benchmark datasets. We have open-sourced the code and model weights to encourage further research into aligning LLM-based AI agents with enhanced supervision efficiency, improved controllability, and scalable oversight.
SALMON: Self-Alignment with Principle-Following Reward Models
Zhiqing Sun Yikang Shen Hongxin Zhang Qinhong Zhou Zhenfang Chen David Daniel Cox Yiming Yang Chuang Gan