activity
20222026
most citedModels of human preference for learning reward functions

8 citations · 9 across the 7 of their papers we have counts for

collaborators

9 papers

cs.AI2026

Mitigating Social Sycophancy via Pluralistic Preference Optimization

Stephane Hatgis-Kessell, Myra Cheng, Xiaoxuan Hou +4

Personal advice, including relationship advice, now ranks among the most common uses of generative AI. But language models (LMs) exhibit sycophancy: they affirm users much more oft…

cs.LG2026

Specifying Reward Functions for RL Without Environment Sampling

Stephane Hatgis-Kessell, W. Bradley Knox, Emma Brunskill

Enabling human stakeholders to specify reward functions that lead to their desired outcomes is a key challenge in deploying reinforcement learning agents. Preference-based methods…

cs.CY2026

Estimating time spent on work tasks

Stephane Hatgis-Kessell, Tomás Aguirre, Alexander Wan +1

The task-based framework in economics models occupations as bundles of tasks. It is the standard lens for understanding how technology affects work: a new technology changes the co…

cs.CY2026

Economic Evaluations of Language Models

Alexander Wan, Stephane Hatgis-Kessell, Tomás Aguirre +2

Language models perform economically valuable work, yet they are not currently assessed for how well they perform every economically valuable task. We introduce EconEvals as an ope…

cs.LG2026

When are LLMs Sufficient Policy Optimizers for Sequential RL Tasks?

Stephane Hatgis-Kessell, Emma Brunskill

We study when large language models (LLMs) can serve as effective black-box policy optimizers for reinforcement learning (RL) tasks, i.e., when can we replace classical RL algorith…

cs.AI2025

Repairing Reward Functions with Feedback to Mitigate Reward Hacking

Stephane Hatgis-Kessell, Logan Mondal Bhamidipaty, Emma Brunskill

Human-designed reward functions for reinforcement learning (RL) agents are frequently misaligned with the humans' true, unobservable objectives, and thus act only as proxies. Optim…

cs.LG2025

Influencing Humans to Conform to Preference Models for RLHF

Stephane Hatgis-Kessell, W. Bradley Knox, Serena Booth +1

Designing a reinforcement learning from human feedback (RLHF) algorithm to approximate a human's unobservable reward function requires assuming, implicitly or explicitly, a model o…

cs.LG2023★ 1 cited

Learning Optimal Advantage from Preferences and Mistaking it for Reward

W. Bradley Knox, Stephane Hatgis-Kessell, Sigurdur Orn Adalgeirsson +4

We consider algorithms for learning reward functions from human preferences over pairs of trajectory segments, as used in reinforcement learning from human feedback (RLHF). Most re…

cs.LG2022★ 8 cited

Models of human preference for learning reward functions

W. Bradley Knox, Stephane Hatgis-Kessell, Serena Booth +3

The utility of reinforcement learning is limited by the alignment of reward functions with the interests of human stakeholders. One promising method for alignment is to learn the r…