论文标题
代理行为的本地和全球解释:将策略摘要与显着图集成
Local and Global Explanations of Agent Behavior: Integrating Strategy Summaries with Saliency Maps
论文作者
论文摘要
随着增强学习的进步(RL),现在正在医疗保健和运输等高风险应用领域中开发代理。解释这些代理人的行为是具有挑战性的,因为它们所作的环境具有较大的状态空间,并且他们的决策可能会受到延迟奖励的影响,从而难以分析其行为。为了解决这个问题,已经开发了几种方法。一些方法试图传达代理商的$ \ textit {global} $行为,描述了其在不同状态下采取的动作。设计$ \ textit {local} $说明的其他方法提供了有关代理在特定状态下决策的信息。在本文中,我们结合了全球和本地的解释方法,并评估了它们的共同和单独的贡献,从而(据我们所知)首次对RL代理的本地和全球解释进行了首次用户研究。具体而言,我们扩大了策略摘要,这些策略摘要从具有显着性图的代理商的模拟中提取重要的状态轨迹,这些图显示了代理商参与的信息。我们的结果表明,在摘要(全球信息)中包含哪些国家的选择强烈影响人们对代理人的理解:参与者显示了包括重要状态的摘要,这些摘要显着超过了在随机选择的世界范围内以代理行为表现出来的参与者。我们发现与显着图(本地信息)增强示范的结果混合的结果,因为在大多数情况下,显着图的添加并不能显着提高性能。但是,我们确实找到了一些证据,表明显着图可以帮助用户更好地了解该代理商在决策中依赖的信息,这为将来的工作提供了途径,可以进一步改善RL代理的解释。
With advances in reinforcement learning (RL), agents are now being developed in high-stakes application domains such as healthcare and transportation. Explaining the behavior of these agents is challenging, as the environments in which they act have large state spaces, and their decision-making can be affected by delayed rewards, making it difficult to analyze their behavior. To address this problem, several approaches have been developed. Some approaches attempt to convey the $\textit{global}$ behavior of the agent, describing the actions it takes in different states. Other approaches devised $\textit{local}$ explanations which provide information regarding the agent's decision-making in a particular state. In this paper, we combine global and local explanation methods, and evaluate their joint and separate contributions, providing (to the best of our knowledge) the first user study of combined local and global explanations for RL agents. Specifically, we augment strategy summaries that extract important trajectories of states from simulations of the agent with saliency maps which show what information the agent attends to. Our results show that the choice of what states to include in the summary (global information) strongly affects people's understanding of agents: participants shown summaries that included important states significantly outperformed participants who were presented with agent behavior in a randomly set of chosen world-states. We find mixed results with respect to augmenting demonstrations with saliency maps (local information), as the addition of saliency maps did not significantly improve performance in most cases. However, we do find some evidence that saliency maps can help users better understand what information the agent relies on in its decision making, suggesting avenues for future work that can further improve explanations of RL agents.