Criticality-Based Advice in Reinforcement Learning (Student Abstract)

One of the ways to make reinforcement learning (RL) more efficient is by utilizing human advice. Since human advice is expensive, the central question in advice-based reinforcement learning is, how to decide in which states the agent should ask for advice. To approach this challenge, various advice strategies have been proposed. Although all of these strategies distribute advice more efficiently than naive strategies, they rely solely on the agent's estimate of the action-value function, and therefore, are rather inefficient when this estimate is not accurate, in particular, in the early stages of the learning process. To address this weakness, we present an approach to advice-based RL, in which the human's role is not limited to giving advice in chosen states, but also includes hinting a-priori, before the learning procedure, in which sub-domains of the state space the agent might require more advice. For this purpose we use the concept of critical: states in which choosing the proper action is more important than in other states.