Research talk: Breaking the deadly triad with a target network

Speaker: Shangtong Zhang, PhD Student, Oxford University The deadly triad refers to the instability of an off-policy reinforcement learning (RL) algorithm when it employs function approximation and bootstrapping simultaneously, and this is a major challenge in off-policy RL. Join PhD student Shangtong Zhang, from the WhiRL group at the University of Oxford, to learn how the target network can be used as a tool for theoretically breaking the deadly triad. Together, you’ll explore how to theoretically understand the conventional wisdom that a target network stabilizes training, a novel target network update rule that augments the commonly used Polyak-averaging style update with two projections, and how a target network can be used in linear off-policy RL algorithms, in both prediction and control settings, as well as both discounted and average-reward Markov decision processes. Learn more about the 2021 Microsoft Research Summit: