Perspectives for Direct Interpretability in Multi-Agent Deep Reinforcement Learning
Yoann Poupart, Aurélie Beynier, Nicolas Maudet
TL;DR
The paper addresses the interpretability gap in Multi-Agent Deep Reinforcement Learning (MADRL) by advocating direct, post-hoc interpretability methods that extract explanations from trained deep networks without altering architectures. It surveys and contextualizes a range of methods—feature importance, prototypes, latent manipulation, and circuit analysis—and maps them to single-agent, multi-agent, and training-process challenges. Key contributions include a taxonomy for applying direct interpretability in MADRL, a synthesis of methods across agent roles and training stages, and proposed directions for team identification, swarm coordination, and sample efficiency. The work highlights the practical significance of interpretable MADRL systems for safety, accountability, and governance in real-world applications, while also calling for robust evaluation protocols to address limitations such as explanation illusions and causal disentanglement.
Abstract
Multi-Agent Deep Reinforcement Learning (MADRL) was proven efficient in solving complex problems in robotics or games, yet most of the trained models are hard to interpret. While learning intrinsically interpretable models remains a prominent approach, its scalability and flexibility are limited in handling complex tasks or multi-agent dynamics. This paper advocates for direct interpretability, generating post hoc explanations directly from trained models, as a versatile and scalable alternative, offering insights into agents' behaviour, emergent phenomena, and biases without altering models' architectures. We explore modern methods, including relevance backpropagation, knowledge edition, model steering, activation patching, sparse autoencoders and circuit discovery, to highlight their applicability to single-agent, multi-agent, and training process challenges. By addressing MADRL interpretability, we propose directions aiming to advance active topics such as team identification, swarm coordination and sample efficiency.
