Learning Correlated Reward Models: Statistical Barriers and Opportunities

Fuente: arXiv
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Autori principali: Cherapanamjeri, Yeshwanth, Daskalakis, Constantinos, Farina, Gabriele, Mohammadpour, Sobhan
Natura: Preprint
Pubblicazione: 2025
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author Cherapanamjeri, Yeshwanth
Daskalakis, Constantinos
Farina, Gabriele
Mohammadpour, Sobhan
author_facet Cherapanamjeri, Yeshwanth
Daskalakis, Constantinos
Farina, Gabriele
Mohammadpour, Sobhan
contents Random Utility Models (RUMs) are a classical framework for modeling user preferences and play a key role in reward modeling for Reinforcement Learning from Human Feedback (RLHF). However, a crucial shortcoming of many of these techniques is the Independence of Irrelevant Alternatives (IIA) assumption, which collapses \emph{all} human preferences to a universal underlying utility function, yielding a coarse approximation of the range of human preferences. On the other hand, statistical and computational guarantees for models avoiding this assumption are scarce. In this paper, we investigate the statistical and computational challenges of learning a \emph{correlated} probit model, a fundamental RUM that avoids the IIA assumption. First, we establish that the classical data collection paradigm of pairwise preference data is \emph{fundamentally insufficient} to learn correlational information, explaining the lack of statistical and computational guarantees in this setting. Next, we demonstrate that \emph{best-of-three} preference data provably overcomes these shortcomings, and devise a statistically and computationally efficient estimator with near-optimal performance. These results highlight the benefits of higher-order preference data in learning correlated utilities, allowing for more fine-grained modeling of human preferences. Finally, we validate these theoretical guarantees on several real-world datasets, demonstrating improved personalization of human preferences.
format Preprint
id arxiv_https___arxiv_org_abs_2510_15839
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Learning Correlated Reward Models: Statistical Barriers and Opportunities
Cherapanamjeri, Yeshwanth
Daskalakis, Constantinos
Farina, Gabriele
Mohammadpour, Sobhan
Machine Learning
Econometrics
Random Utility Models (RUMs) are a classical framework for modeling user preferences and play a key role in reward modeling for Reinforcement Learning from Human Feedback (RLHF). However, a crucial shortcoming of many of these techniques is the Independence of Irrelevant Alternatives (IIA) assumption, which collapses \emph{all} human preferences to a universal underlying utility function, yielding a coarse approximation of the range of human preferences. On the other hand, statistical and computational guarantees for models avoiding this assumption are scarce. In this paper, we investigate the statistical and computational challenges of learning a \emph{correlated} probit model, a fundamental RUM that avoids the IIA assumption. First, we establish that the classical data collection paradigm of pairwise preference data is \emph{fundamentally insufficient} to learn correlational information, explaining the lack of statistical and computational guarantees in this setting. Next, we demonstrate that \emph{best-of-three} preference data provably overcomes these shortcomings, and devise a statistically and computationally efficient estimator with near-optimal performance. These results highlight the benefits of higher-order preference data in learning correlated utilities, allowing for more fine-grained modeling of human preferences. Finally, we validate these theoretical guarantees on several real-world datasets, demonstrating improved personalization of human preferences.
title Learning Correlated Reward Models: Statistical Barriers and Opportunities
topic Machine Learning
Econometrics
url https://arxiv.org/abs/2510.15839