mlsanityData to 7 Oct 2026

Uncertainty-Penalized Reinforcement Learning from Human Feedback with Diverse Reward LoRA Ensembles

arXiv 2401.00243 ↗First posted 30 Dec 2023cs.LGcited by 55

On the map: LLM alignment / RLHF / preference optimisation → Reward modeling and RLHF

Abstract (arXiv)

Reinforcement learning from human feedback (RLHF) emerges as a promising paradigm for aligning large language models (LLMs). However, a notable challenge in RLHF is overoptimization, where beyond a certain threshold, the pursuit of higher rewards leads to a decline in human preferences. In this paper, we observe the weakness of KL regularization which is commonly employed in existing RLHF methods to address overoptimization. To mitigate this limitation, we scrutinize the RLHF objective in the offline dataset and propose uncertainty-penalized RLHF (UP-RLHF), which incorporates uncertainty regularization during RL-finetuning. To enhance the uncertainty quantification abilities for reward models, we first propose a diverse low-rank adaptation (LoRA) ensemble by maximizing the nuclear norm of LoRA matrix concatenations. Then we optimize policy models utilizing penalized rewards, determined by both rewards and uncertainties provided by the diverse reward LoRA ensembles. Our experimental results, based on two real human preference datasets, showcase the effectiveness of diverse reward LoRA ensembles in quantifying reward uncertainty. Additionally, uncertainty regularization in UP-RLHF proves to be pivotal in mitigating overoptimization, thereby contributing to the overall performance.

Key facts. Cited by 55 papers in the map (data through 7 Oct 2026). Placed in Reward modeling and RLHF, one of 10 directions in LLM alignment / RLHF / preference optimisation. Builds on 43 of its 54 references that are in the map. First posted on arXiv 30 Dec 2023.

Builds on

43 of 54 references.

Closest ancestors · 14

Same direction, newest first

  1. 2023Policy Optimization in RLHF: The Impact of Out-of-preference Data17 Dec
  2. 2023Helping or Herding? Reward Model Ensembles Mitigate but do not Eliminate Reward Hacking14 Dec
  3. 2023Confronting Reward Model Overoptimization with Constrained RLHF6 Oct
  4. 2023Reward Model Ensembles Help Mitigate Overoptimization4 Oct
  5. 2023Pairwise Proximal Policy Optimization: Harnessing Relative Feedback for LLM Alignment30 Sep
  6. 2023Reinforced Self-Training (ReST) for Language Modeling17 Aug
  7. 2023DeepSpeed-Chat: Easy, Fast and Affordable RLHF Training of ChatGPT-like Models at All Scales2 Aug
  8. 2023Open Problems and Fundamental Limitations of Reinforcement Learning from Human Feedback27 Jul
  9. 2023Direct Preference Optimization: Your Language Model is Secretly a Reward Model29 May
  10. 2023RRHF: Rank Responses to Align Language Models with Human Feedback without tears11 Apr
  11. 2022Scaling Laws for Reward Model Overoptimization19 Oct
  12. 2022Training a Helpful and Harmless Assistant with Reinforcement Learning from Human Feedback12 Apr
2 more
  1. 2022Uncertainty Estimation for Language Reward Models14 Mar
  2. 2019Fine-Tuning Language Models from Human Preferences18 Sep

Other references · 29

  1. 2020Language Models are Few-Shot Learnerscited by 32,199
  2. 2022Training language models to follow instructions with human feedbackcited by 15,712
  3. 2017Proximal Policy Optimization Algorithmscited by 14,441
  4. 2023Llama 2: Open Foundation and Fine-Tuned Chat Modelscited by 12,865
  5. 2015Dropout as a Bayesian Approximation: Representing Model Uncertainty in Deep Learningcited by 4,416
  6. 2022OPT: Open Pre-trained Transformer Language Modelscited by 3,464
  7. 2020Learning to summarize from human feedbackcited by 2,562
  8. 2015Trust Region Policy Optimizationcited by 2,503
  9. 2016Asynchronous Methods for Deep Reinforcement Learningcited by 2,218
  10. 2020Offline Reinforcement Learning: Tutorial, Review, and Perspectives on Open Problemscited by 1,873
  11. 2022Red Teaming Language Models with Language Modelscited by 983
  12. 2023A General Theoretical Paradigm to Understand Learning from Human Preferencescited by 906
17 more
  1. 2019When to Trust Your Model: Model-Based Policy Optimizationcited by 753
  2. 2019Advantage-Weighted Regression: Simple and Scalable Off-Policy Reinforcement Learningcited by 750
  3. 2021A Survey of Uncertainty in Deep Neural Networkscited by 675
  4. 2023Baichuan 2: Open Large-scale Language Modelscited by 664
  5. 2020MOReL : Model-Based Offline Reinforcement Learningcited by 582
  6. 2021Understanding Dataset Difficulty with V-Usable Informationcited by 288
  7. 2023Preference Ranking Optimization for Human Alignmentcited by 283
  8. 2019Self-Supervised Exploration via Disagreementcited by 263
  9. 2022Is Reinforcement Learning (Not) for Natural Language Processing: Benchmarks, Baselines, and Building Blocks for Natural Language Policy Optimizationcited by 244
  10. 2022Offline RL for Natural Language Generation with Implicit Language Q Learningcited by 137
  11. 2022Pessimistic Bootstrapping for Uncertainty-Driven Offline Reinforcement Learningcited by 125
  12. 2023Aligning Language Models with Preferences through f-divergence Minimizationcited by 118
  13. 2022On Reinforcement Learning and Distribution Matching for Fine-Tuning Language Models with no Catastrophic Forgettingcited by 80
  14. 2023LoRA ensembles for large language model fine-tuningcited by 65
  15. 2021Revisiting Design Choices in Offline Model-Based Reinforcement Learningcited by 50
  16. 2023Fine-Tuning Language Models with Advantage-Induced Policy Alignmentcited by 48
  17. 2022A Review of Uncertainty for Deep Reinforcement Learningcited by 36

Built on by

Cited by year (2026 to 7 Oct)

Citing papers per year: 2024: 26; 2025: 14; 2026: 15.

55 papers.

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  1. 2024Disentangling Length from Quality in Direct Preference Optimizationcited by 194
  2. 2024Scaling Laws for Reward Model Overoptimization in Direct Alignment Algorithmscited by 139
  3. 2024InfoRM: Mitigating Reward Hacking in RLHF via Information-Theoretic Reward Modelingcited by 76
  4. 2024Robust Preference Optimization through Reward Model Distillationcited by 67
  5. 2024A Survey on LoRA of Large Language Modelscited by 67
  6. 2024Merge, Ensemble, and Cooperate! A Survey on Collaborative Strategies in the Era of Large Language Modelscited by 43
  7. 2024Uncertainty quantification in fine-tuned LLMs using LoRA ensemblescited by 35
  8. 2024Bayesian Reward Models for LLM Alignmentcited by 35
  9. 2024Comprehensive Overview of Reward Engineering and Shaping in Advancing Reinforcement Learning Applicationscited by 34
  10. 2024Overcoming Reward Overoptimization via Adversarial Policy Optimization with Lightweight Uncertainty Estimationcited by 33
  11. 2024Reward-Robust RLHF in LLMscited by 32
  12. 2024Eliminating Biased Length Reliance of Direct Preference Optimization via Down-Sampled KL Divergencecited by 29
38 more
  1. 2024Post-hoc Reward Calibration: A Case Study on Length Biascited by 29
  2. 2024Transforming and Combining Rewards for Aligning Large Language Modelscited by 24
  3. 2024Language Models in Dialogue: Conversational Maxims for Human-AI Interactionscited by 21
  4. 2025The Energy Loss Phenomenon in RLHF: A New Perspective on Mitigating Reward Hackingcited by 18
  5. 2024Towards a Unified View of Preference Learning for Large Language Models: A Surveycited by 17
  6. 2025Adversarial Training of Reward Modelscited by 17
  7. 2024DMoERM: Recipes of Mixture-of-Experts for Effective Reward Modelingcited by 15
  8. 2024Hallucination Detection in LLMs: Fast and Memory-Efficient Fine-Tuned Modelscited by 15
  9. 2024Sail into the Headwind: Alignment via Robust Rewards and Dynamic Labels against Reward Hackingcited by 13
  10. 2025On the Robustness of Reward Models for Language Model Alignmentcited by 13
  11. 2025Ask a Strong LLM Judge when Your Reward Model is Uncertaincited by 13
  12. 2026Real-Time Aligned Reward Model beyond Semanticscited by 12
  13. 2025Ensemble Learning for Large Language Models in Text and Code Generation: A Surveycited by 8
  14. 2024Towards Reliable Alignment: Uncertainty-aware RLHFcited by 7
  15. 2024Improving Instruction Following in Language Models through Proxy-Based Uncertainty Estimationcited by 6
  16. 2024Understanding Likelihood Over-optimisation in Direct Alignment Algorithmscited by 6
  17. 2024Uncertainty-Penalized Direct Preference Optimizationcited by 6
  18. 2024Functional-level Uncertainty Quantification for Calibrated Fine-tuning on LLMscited by 5
  19. 2025Two Minds Better Than One: Collaborative Reward Modeling for LLM Alignmentcited by 5
  20. 2025Proximalized Preference Optimization for Diverse Feedback Types: A Decomposed Perspective on DPOcited by 5
  21. 2025Information-Theoretic Reward Modeling for Stable RLHF: Detecting and Mitigating Reward Hackingcited by 5
  22. 2026Reward Modeling for Reinforcement Learning-Based LLM Reasoning: Design, Challenges, and Evaluationcited by 5
  23. 2025Energy-Based Reward Models for Robust Language Model Alignmentcited by 4
  24. 2025Bayesian Mixture of Experts For Large Language Modelscited by 4
  25. 2026RewardUQ: A Unified Framework for Uncertainty-Aware Reward Modelscited by 3
  26. 2024Beyond Adapter Retrieval: Latent Geometry-Preserving Composition via Sparse Task Projectioncited by 2
  27. 2026Pushing Forward Pareto Frontiers of Proactive Agents with Behavioral Agentic Optimizationcited by 2
  28. 2026From Curiosity to Caution: Mitigating Reward Hacking for Best-of-N with Pessimismcited by 2
  29. 2025Policy Optimized Text-to-Image Pipeline Designcited by 1
  30. 2025Provably Mitigating Corruption, Overoptimization, and Verbosity Simultaneously in Offline and Online RLHF/DPO Alignmentcited by 1
  31. 2026A Unifying Lens on Reward Uncertainty in RLHFcited by 1
  32. 2024Online Self-Preferring Language Modelscited by 0
  33. 2025Towards Reliable, Uncertainty-Aware Alignmentcited by 0
  34. 2025The Silent Scholar Problem: A Probabilistic Framework for Breaking Epistemic Asymmetry in LLM Agentscited by 0
  35. 2026Wasserstein Distributionally Robust Regret Optimization for Reinforcement Learning from Human Feedbackcited by 0
  36. 2026Epistemic Uncertainty for Test-Time Discoverycited by 0
  37. 2026Reinforcement learning to improve large language model-based automated code compliance systemscited by 0
  38. 2026Towards Bridging the Gap Between Offline and Iterative Alignment via Preference Distillationcited by 0

50 most cited of 55 All 55 (JSON)

Similar, not cited

Close in wording, no citation either way

  1. 2025Uncertainty Quantification for Large Language Model Reward Learning under Heterogeneous Human Feedback
  2. 2024Improving Reinforcement Learning from Human Feedback with Efficient Reward Model Ensemble
  3. 2026Reinforcement Learning from Human Feedback: A Statistical Perspective
  4. 2026Uncertainty-Aware Reward Modeling for Stable RLHF
  5. 2024Value-Incentivized Preference Optimization: A Unified Approach to Online and Offline RLHF
  6. 2025Robust Reinforcement Learning from Human Feedback for Large Language Models Fine-Tuning
  7. 2025Off-Policy Corrected Reward Modeling for Reinforcement Learning from Human Feedback
  8. 2025A Shared Low-Rank Adaptation Approach to Personalized RLHF