Exploring TD error as a heuristic for $\sigma$ selection in Q($\sigma$, $\lambda$)

Abstract

In the landscape of TD algorithms, the Q($\sigma$, $\lambda$) algorithm is an algorithm with the ability to perform a multistep backup in an online manner while also successfully unifying the concepts of sampling with using the expectation across all actions for a state. $\sigma \in [0,1]$ indicates the extent to which sampling is used. Selecting the value of σ can be based on characteristics of the current state rather than having a constant value or being time based. This report explores the viability of such a TD-error based scheme.