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Katherine Metcalf

10 accepted papers

2026

Normalized Rewards for Preference Optimization

ICML 2026poster

Direct Alignment Algorithms (DAAs) such as DPO have become a common way to post-train and align LLMs with human preferences. However, DAAs have been observed to over-optimize their implicit reward model and decrease the likelihood of preferred responses. This results in a decrease in the total likel…

Cited by 0SourceScholar
2025

Aligning LLMs by Predicting Preferences from User Writing Samples

ICML 2025poster

Accommodating human preferences is essential for creating aligned LLM agents that deliver personalized and effective interactions. Recent work has shown the potential for LLMs acting as writing agents to infer a description of user preferences. Agent alignment then comes from conditioning on the inf…

2025

Is Your Model Fairly Certain? Uncertainty-Aware Fairness Evaluation for LLMs

ICML 2025poster

The recent rapid adoption of large language models (LLMs) highlights the critical need for benchmarking their fairness. Conventional fairness metrics, which focus on discrete accuracy-based evaluations (i.e., prediction correctness), fail to capture the implicit impact of model uncertainty (e.g., hi…

2025

Steering into New Embedding Spaces: Analyzing Cross-Lingual Alignment Induced by Model Interventions in Multilingual Language Models

ACL 2025long

Aligned representations across languages is a desired property in multilingual large language models (mLLMs), as alignment can improve performance in cross-lingual tasks. Typically alignment requires fine-tuning a model, which is computationally expensive, and sizable language data, which often may…

Cited by 0SourcePDFScholar
2024

Can You Rely on Synthetic Labellers in Preference-Based Reinforcement Learning? It’s Complicated

AAAI 2024technical

Preference-based Reinforcement Learning (PbRL) enables non-experts to train Reinforcement Learning models using preference feedback. However, the effort required to collect preference labels from real humans means that PbRL research primarily relies on synthetic labellers. We validate the most commo…

Cited by 2SourcePDFScholar
2024

On the Limited Generalization Capability of the Implicit Reward Model Induced by Direct Preference Optimization

EMNLP 2024finding

Reinforcement Learning from Human Feedback (RLHF) is an effective approach for aligning language models to human preferences. Central to RLHF is learning a reward function for scoring human preferences. Two main approaches for learning a reward model are 1) training an EXplicit Reward Model (EXRM) a…

2024

Whispering Experts: Neural Interventions for Toxicity Mitigation in Language Models

ICML 2024poster

An important issue with Large Language Models (LLMs) is their undesired ability to generate toxic language. In this work, we show that the neurons responsible for toxicity can be determined by their power to discriminate toxic sentences, and that toxic language can be mitigated by reducing their act…

Cited by 7SourcePDFScholar
2023

On the Role of LIP Articulation in Visual Speech Perception

ICASSP 2023accepted

Generating realistic lip motion from audio to simulate speech production is critical for driving natural character animation. Previous research has shown that traditional metrics used to optimize and assess models for generating lip motion from speech are not a good indicator of subjective opinion o…

Cited by 0SourceScholar
2023

Sample-Efficient Preference-based Reinforcement Learning with Dynamics Aware Rewards

CoRL 2023poster

Preference-based reinforcement learning (PbRL) aligns a robot behavior with human preferences via a reward function learned from binary feedback over agent behaviors. We show that encoding environment dynamics in the reward function improves the sample efficiency of PbRL by an order of magnitude. In…

Cited by 7SourcecodeScholar