🤖 AI Summary
Current explainable reinforcement learning (XRL) lacks objective, actionable metrics for evaluating explanation quality; prevailing approaches rely on subjective human judgments, impeding empirical validation and cross-study comparability. Method: We propose the first objective, behavior-based human evaluation paradigm tailored to debugging and human-AI collaboration tasks. Grounded in observable behavioral outcomes—such as task completion rate, error-correction efficiency, and collaborative response latency—we conduct controlled behavioral tracking experiments in a customized grid-world environment. Contribution/Results: This paradigm overcomes the limitations of subjective assessment by directly linking explanation quality to measurable human performance. Empirical results demonstrate its superior reliability in characterizing explanation efficacy, significantly enhancing reproducibility, cross-method comparability, and epistemic rigor. It establishes the first scientifically grounded, standardized human evaluation benchmark for XRL.
📝 Abstract
Explanation is a fundamentally human process. Understanding the goal and audience of the explanation is vital, yet existing work on explainable reinforcement learning (XRL) routinely does not consult humans in their evaluations. Even when they do, they routinely resort to subjective metrics, such as confidence or understanding, that can only inform researchers of users' opinions, not their practical effectiveness for a given problem. This paper calls on researchers to use objective human metrics for explanation evaluations based on observable and actionable behaviour to build more reproducible, comparable, and epistemically grounded research. To this end, we curate, describe, and compare several objective evaluation methodologies for applying explanations to debugging agent behaviour and supporting human-agent teaming, illustrating our proposed methods using a novel grid-based environment. We discuss how subjective and objective metrics complement each other to provide holistic validation and how future work needs to utilise standardised benchmarks for testing to enable greater comparisons between research.