Off-Policy Evaluation from Logged Human Feedback
This addresses the costly collection of human feedback in AI/ML by enabling model evaluation without new data, though it is incremental as it builds on existing off-policy evaluation methods.
The paper tackles the problem of evaluating new models using existing human feedback from another model, formalizing off-policy evaluation from logged human feedback and proposing estimators that can predict policy values, rank policies, and be optimized.
Learning from human feedback has been central to recent advances in artificial intelligence and machine learning. Since the collection of human feedback is costly, a natural question to ask is if the new feedback always needs to collected. Or could we evaluate a new model with the human feedback on responses of another model? This motivates us to study off-policy evaluation from logged human feedback. We formalize the problem, propose both model-based and model-free estimators for policy values, and show how to optimize them. We analyze unbiasedness of our estimators and evaluate them empirically. Our estimators can predict the absolute values of evaluated policies, rank them, and be optimized.