Sequential Transfer in Reinforcement Learning with a Generative Model
This work addresses sample efficiency in reinforcement learning for agents, but it is incremental as it builds on existing transfer learning and generative model methods.
The paper tackles the problem of reducing sample complexity in reinforcement learning for new tasks by transferring knowledge from previously-solved ones, focusing on quickly identifying optimal solutions using a generative model, and derives PAC bounds showing benefits and empirically verifies findings in simulated domains.
We are interested in how to design reinforcement learning agents that provably reduce the sample complexity for learning new tasks by transferring knowledge from previously-solved ones. The availability of solutions to related problems poses a fundamental trade-off: whether to seek policies that are expected to achieve high (yet sub-optimal) performance in the new task immediately or whether to seek information to quickly identify an optimal solution, potentially at the cost of poor initial behavior. In this work, we focus on the second objective when the agent has access to a generative model of state-action pairs. First, given a set of solved tasks containing an approximation of the target one, we design an algorithm that quickly identifies an accurate solution by seeking the state-action pairs that are most informative for this purpose. We derive PAC bounds on its sample complexity which clearly demonstrate the benefits of using this kind of prior knowledge. Then, we show how to learn these approximate tasks sequentially by reducing our transfer setting to a hidden Markov model and employing spectral methods to recover its parameters. Finally, we empirically verify our theoretical findings in simple simulated domains.