In collaborative tasks, autonomous agents fall short of humans in their capability to quickly adapt to new and unfamiliar teammates. We posit that a limiting factor for zero-shot coordination is the lack of shared task abstractions, a mechanism humans rely on to implicitly align with teammates. To address this gap, we introduce HA: Hierarchical Ad Hoc Agents, a framework leveraging hierarchical reinforcement learning to mimic the structured approach humans use in collaboration. We evaluate HA in the Overcooked environment, demonstrating statistically significant improvement over existing baselines when paired with both unseen agents and humans, providing better resilience to environmental shifts, and outperforming all state-of-the-art methods.
View on arXiv@article{aroca-ouellette2025_2505.04579, title={ Implicitly Aligning Humans and Autonomous Agents through Shared Task Abstractions }, author={ Stéphane Aroca-Ouellette and Miguel Aroca-Ouellette and Katharina von der Wense and Alessandro Roncone }, journal={arXiv preprint arXiv:2505.04579}, year={ 2025 } }