Publications

Off-Policy Evaluation in Embedded Spaces

Causal Inference Challenges in Sequential Decision Making: Bridging Theory and Practice, A NeurIPS 2021 Workshop

Publication date: December 14, 2021

Jaron J.R Lee, David Arbour, Georgios Theocharous

Off-policy evaluation methods are important in recommendation systems and search engines, whereby data collected under an old logging policy is used to predict the performance of a new target policy. However, in practice most systems are not observed to recommend most of the possible actions, which is an issue since existing methods require that the probability of the target policy recommending an item can only be non-zero when the probability of the logging policy is non-zero (known as absolute continuity). To circumvent this issue, we explore the use of action embeddings. By representing contexts and actions in an embedding space, we are able to share information to extrapolate behaviors for actions and contexts previously unseen.

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Research Area:  Adobe Research iconAI & Machine Learning