We study how to effectively leverage expert feedback to learn sequential decision-making policies. We focus on problems with sparse rewards and long time horizons, which typically pose significant challenges in reinforcement learning. We propose an algorithmic framework, called hierarchical guidance, that leverages the hierarchical structure of the underlying problem to integrate different modes of expert interaction. Our framework can incorporate different combinations of imitation learning (IL) and reinforcement learning (RL) at different levels, leading to dramatic reductions in both expert effort and cost of exploration. Using long-horizon benchmarks, including Montezuma’s Revenge, we demonstrate that our approach can learn significantly faster than hierarchical RL, and be significantly more label-efficient than standard IL. We also theoretically analyze labeling cost for certain instantiations of our framework. Read More

#human, #observational-learning, #reinforcement-learning

Imitation is a key part in the human learning. In the high-tech world, if you are not an innovator, you want to be a quick follower. In reinforcement learning, we maximize the rewards for our actions. Model-based RL focuses on the model (the system dynamics) to optimize our decisions while Policy Gradient methods improve the policy for better rewards.

On the other hand, Imitation learning focuses on imitating expert demonstrations. Read More

#human, #observational-learning, #reinforcement-learning