Timo Kaufmann

Reinforcement learning from human feedback (RLHF) is a variant of reinforcement learning (RL) that learns from human feedback instead of relying on an engineered reward function. Building on prior work on the related setting of preference-based reinforcement learning (PbRL), it stands at the intersection of artificial intelligence and human-computer interaction. This positioning offers a promising avenue to enhance the performance and adaptability of intelligent systems while also improving the alignment of their objectives with human values. The training of large language models (LLMs) has impressively demonstrated this potential in recent years, where RLHF played a decisive role in targeting the model’s capabilities toward human objectives. This article provides a comprehensive overview of the fundamentals of RLHF, exploring the intricate dynamics between machine agents and human input. While recent focus has been on RLHF for LLMs, our survey adopts a broader perspective, examining the diverse applications and wide-ranging impact of the technique. We delve into the core principles that underpin RLHF, shedding light on the symbiotic relationship between algorithms and human feedback, and discuss the main research trends in the field. By synthesizing the current landscape of RLHF research, this article aims to provide researchers as well as practitioners with a comprehensive understanding of this rapidly growing field of research.

Reinforcement learning from human feedback (RLHF) is a variant of reinforcement learning (RL) that does not require an engineered reward function but instead learns from human feedback. Due to its increasing popularity, various authors have studied how to learn an accurate reward model from only few samples, making optimal use of this feedback. Because of the cost and complexity of user studies, however, this research is often conducted with synthetic human feedback. Such feedback can be generated by evaluating behavior based on ground-truth rewards which are available for some benchmark tasks. While this setting can help evaluate some aspects of RLHF, it differs from practical settings in which synthetic feedback is not available. Working with real human feedback brings additional challenges that cannot be observed with synthetic feedback, including fatigue, inter-rater inconsistencies, delay, misunderstandings, and modality-dependent difficulty. We describe and discuss some of these challenges together with current practices and opportunities for further research in this paper.

In this paper, we advocate for the potential of reinforcement learning from human feedback (RLHF) with self-supervised pretraining to increase the viability of reinforcement learning (RL) for real-world tasks, especially in the context of cyber-physical systems (CPS). We identify potential benefits of self-supervised pretraining in terms of the query sample complexity, safety, robustness, reward exploration and transfer. We believe that exploiting these benefits, combined with the generally improving sample efficiency of RL, will likely enable RL and RLHF to play an increasing role in CPS in the future.