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Ruizhe Shi

6 accepted papers

2026

Understanding the Performance Gap in Preference Learning: A Dichotomy of RLHF and DPO

ICML 2026poster

We present a fine-grained theoretical analysis of the performance gap between reinforcement learning from human feedback (RLHF) and direct preference optimization (DPO) under a representation gap. Our study decomposes this gap into two sources: an explicit representation gap under exact optimization…

Cited by 0SourcecodeScholar
2025

The Crucial Role of Samplers in Online Direct Preference Optimization

ICLR 2025poster

Direct Preference Optimization (DPO) has emerged as a stable, scalable, and efficient solution for language model alignment. Despite its empirical success, the optimization properties, particularly the impact of samplers on its convergence rates, remain under-explored. In this paper, we provide a ri…

2024

Decoding-Time Language Model Alignment with Multiple Objectives

NeurIPS 2024poster

Aligning language models (LMs) to human preferences has emerged as a critical pursuit, enabling these models to better serve diverse user needs. Existing methods primarily focus on optimizing LMs for a single reward function, limiting their adaptability to varied objectives. Here, we propose $\text…

2024

Rethinking Transformers in Solving POMDPs

ICML 2024poster

Sequential decision-making algorithms such as reinforcement learning (RL) in real-world scenarios inevitably face environments with partial observability. This paper scrutinizes the effectiveness of a popular architecture, namely Transformers, in Partially Observable Markov Decision Processes (POMDP…

2024

Unleashing the Power of Pre-trained Language Models for Offline Reinforcement Learning

ICLR 2024poster

Offline reinforcement learning (RL) aims to find a near-optimal policy using pre-collected datasets. Given recent advances in Large Language Models (LLMs) and their few-shot learning prowess, this paper introduces $\textbf{La}$nguage Models for $\textbf{Mo}$tion Control ($\textbf{LaMo}$), a general…

2023

H-InDex: Visual Reinforcement Learning with Hand-Informed Representations for Dexterous Manipulation

NeurIPS 2023poster

Human hands possess remarkable dexterity and have long served as a source of inspiration for robotic manipulation. In this work, we propose a human $\textbf{H}$and-$\textbf{In}$formed visual representation learning framework to solve difficult $\textbf{Dex}$terous manipulation tasks ($\textbf{H-InDe…

Cited by 21SourcePDFScholar