Nash Learning from Human Feedback

Paper: http://arxiv.org/abs/2312.00886

### Purpose

The paper introduces a new framework called Nash Learning from Human Feedback (NLHF), which is a radical departure from the usual Reinforcement Learning from Human Feedback (RLHF). Instead of learning a reward model, NLHF focuses on learning a preference model and aims to compute the Nash equilibrium based on this model.

### Methods

The researchers used a preference model that takes two responses and produces a preference score, indicating which response is preferred in a given context. They then used a deep reinforcement learning algorithm to approximate the Nash equilibrium of a two-player game where actions are responses and payoffs are determined by the preference model.

### Key Findings

The key findings are that the Nash equilibrium can better align with the diversity of human preferences compared to traditional RLHF. The Nash-MD algorithm introduced in the paper converges to the Nash equilibrium without the need to store past policies, which is a big deal for large language models (LLMs) with their hefty memory requirements.

### Discussion

The paper discusses how the Nash equilibrium represents a policy that consistently produces responses preferred by the preference model over any alternative policy. This approach has the potential to capture a wider range of human preferences and is policy-independent.

### Critiques

While the paper presents a novel approach, it's still early days, and the real-world effectiveness of NLHF compared to traditional RLHF remains to be seen. The experiments conducted are more proof of concept than a definitive statement of superiority.

### Tags

#alignment #gametheory #nashequilibrium #AI #machine learning