mlsanityData to 14 Oct 2026

RRM: Robust Reward Model Training Mitigates Reward Hacking

arXiv 2409.13156 ↗First posted 20 Sep 2024cs.CLcited by 76

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

Abstract (arXiv)

Reward models (RMs) play a pivotal role in aligning large language models (LLMs) with human preferences. However, traditional RM training, which relies on response pairs tied to specific prompts, struggles to disentangle prompt-driven preferences from prompt-independent artifacts, such as response length and format. In this work, we expose a fundamental limitation of current RM training methods, where RMs fail to effectively distinguish between contextual signals and irrelevant artifacts when determining preferences. To address this, we introduce a causal framework that learns preferences independent of these artifacts and propose a novel data augmentation technique designed to eliminate them. Extensive experiments show that our approach successfully filters out undesirable artifacts, yielding a more robust reward model (RRM). Our RRM improves the performance of a pairwise reward model trained on Gemma-2-9b-it, on RewardBench, increasing accuracy from 80.61% to 84.15%. Additionally, we train two DPO policies using both the RM and RRM, demonstrating that the RRM significantly enhances DPO-aligned policies, improving MT-Bench scores from 7.27 to 8.31 and length-controlled win-rates in AlpacaEval-2 from 33.46% to 52.49%.

Key facts. Cited by 76 papers in the map (data through 14 Oct 2026). Placed in Reward modeling and RLHF, one of 10 directions in LLM alignment / RLHF / preference optimisation. Builds on 48 of its 64 references that are in the map. First posted on arXiv 20 Sep 2024.

Builds on

48 of 64 references.

Closest ancestors · 22

Same direction, newest first

  1. 2024From Lists to Emojis: How Format Bias Affects Model Alignment18 Sep
  2. 2024Boosting Reward Model with Preference-Conditional Multi-Aspect Synthetic Data Generation22 Jul
  3. 2024BOND: Aligning LLMs with Best-of-N Distillation19 Jul
  4. 2024WARP: On the Benefits of Weight Averaged Rewarded Policies24 Jun
  5. 2024Interpretable Preferences via Multi-Objective Reward Modeling and Mixture-of-Experts18 Jun
  6. 2024RLHF Workflow: From Reward Modeling to Online RLHF13 May
  7. 2024RewardBench: Evaluating Reward Models for Language Modeling20 Mar
  8. 2024ODIN: Disentangled Reward Mitigates Hacking in RLHF11 Feb
  9. 2024WARM: On the Benefits of Weight Averaged Reward Models22 Jan
  10. 2023Iterative Preference Learning from Human Feedback: Bridging Theory and Practice for RLHF under KL-Constraint18 Dec
  11. 2023Helping or Herding? Reward Model Ensembles Mitigate but do not Eliminate Reward Hacking14 Dec
  12. 2023Loose lips sink ships: Mitigating Length Bias in Reinforcement Learning from Human Feedback8 Oct
10 more
  1. 2023A Long Way to Go: Investigating Length Correlations in RLHF5 Oct
  2. 2023Reward Model Ensembles Help Mitigate Overoptimization4 Oct
  3. 2023The Trickle-down Impact of Reward (In-)consistency on RLHF28 Sep
  4. 2023Direct Preference Optimization: Your Language Model is Secretly a Reward Model29 May
  5. 2023SLiC-HF: Sequence Likelihood Calibration with Human Feedback17 May
  6. 2023RAFT: Reward rAnked FineTuning for Generative Foundation Model Alignment13 Apr
  7. 2022Scaling Laws for Reward Model Overoptimization19 Oct
  8. 2022Training a Helpful and Harmless Assistant with Reinforcement Learning from Human Feedback12 Apr
  9. 2019Fine-Tuning Language Models from Human Preferences18 Sep
  10. 2017Deep reinforcement learning from human preferences12 Jun

Other references · 26

  1. 2023GPT-4 Technical Reportcited by 18,396
  2. 2022Training language models to follow instructions with human feedbackcited by 15,971
  3. 2017Proximal Policy Optimization Algorithmscited by 15,215
  4. 2023Judging LLM-as-a-Judge with MT-Bench and Chatbot Arenacited by 8,626
  5. 2022Constitutional AI: Harmlessness from AI Feedbackcited by 3,050
  6. 2020Learning to summarize from human feedbackcited by 2,588
  7. 2021Calibrate Before Use: Improving Few-Shot Performance of Language Modelscited by 1,392
  8. 2024SimPO: Simple Preference Optimization with a Reference-Free Rewardcited by 963
  9. 2023A General Theoretical Paradigm to Understand Learning from Human Preferencescited by 912
  10. 2024Length-Controlled AlpacaEval: A Simple Way to Debias Automatic Evaluatorscited by 897
  11. 2023BeaverTails: Towards Improved Safety Alignment of LLM via a Human-Preference Datasetcited by 860
  12. 2023AlpacaFarm: A Simulation Framework for Methods that Learn from Human Feedbackcited by 748
14 more
  1. 2023LLM-Blender: Ensembling Large Language Models with Pairwise Ranking and Generative Fusioncited by 564
  2. 2023Statistical Rejection Sampling Improves Preference Optimizationcited by 323
  3. 2021Understanding Dataset Difficulty with V-Usable Informationcited by 291
  4. 2024Direct Language Model Alignment from Online AI Feedbackcited by 260
  5. 2024Disentangling Length from Quality in Direct Preference Optimizationcited by 196
  6. 2020Implementation Matters in Deep Policy Gradients: A Case Study on PPO and TRPOcited by 186
  7. 2024Sycophancy to Subterfuge: Investigating Reward-Tampering in Large Language Modelscited by 178
  8. 2024BoNBoN Alignment for Large Language Models and the Sweetness of Best-of-n Samplingcited by 121
  9. 2024LiPO: Listwise Preference Optimization through Learning-to-Rankcited by 96
  10. 2024Human Alignment of Large Language Models through Online Preference Optimisationcited by 91
  11. 2019On the Weaknesses of Reinforcement Learning for Neural Machine Translationcited by 82
  12. 2024Building Math Agents with Multi-Turn Iterative Preference Learningcited by 66
  13. 2024Offline Regularised Reinforcement Learning for Large Language Models Alignmentcited by 48
  14. 2023Predicting Text Preference Via Structured Comparative Reasoningcited by 6

Built on by

Cited by year (2026 to 14 Oct)

Citing papers per year: 2024: 3; 2025: 38; 2026: 35.

76 papers.

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By area:

  1. 2025LLM Post-Training: A Deep Dive into Reasoning Large Language Modelscited by 135
  2. 2025Reward Shaping to Mitigate Reward Hacking in RLHFcited by 88
  3. 2024Self-Generated Critiques Boost Reward Modeling for Language Modelscited by 71
  4. 2025A Comprehensive Survey of Reward Models: Taxonomy, Applications, Challenges, and Futurecited by 53
  5. 2025AdvancedIF: Rubric-Based Benchmarking and Reinforcement Learning for Advancing LLM Instruction Followingcited by 51
  6. 2025Inference-Time Reward Hacking in Large Language Modelscited by 34
  7. 2026Reward Hacking in the Era of Large Models: Mechanisms, Emergent Misalignment, Challengescited by 33
  8. 2025Diversity-Incentivized Exploration for Versatile Reasoningcited by 28
  9. 2024CARMO: Dynamic Criteria Generation for Context-Aware Reward Modellingcited by 22
  10. 2025Virtual Agent Economiescited by 21
  11. 2024RainbowPO: A Unified Framework for Combining Improvements in Preference Optimizationcited by 19
  12. 2025Robust Reward Modeling via Causal Rubricscited by 19
38 more
  1. 2025Adversarial Training of Reward Modelscited by 18
  2. 2025Encouraging Good Processes Without the Need for Good Answers: Reinforcement Learning for LLM Agent Planningcited by 17
  3. 2025Think-RM: Enabling Long-Horizon Reasoning in Generative Reward Modelscited by 16
  4. 2025Pre-Trained Policy Discriminators are General Reward Modelscited by 15
  5. 2025Alignment and Safety in Large Language Models: Safety Mechanisms, Training Paradigms, and Emerging Challengescited by 15
  6. 2025Sailing by the Stars: A Survey on Reward Models and Learning Strategies for Learning from Rewardscited by 14
  7. 2025On the Robustness of Reward Models for Language Model Alignmentcited by 13
  8. 2025Flattery, Fluff, and Fog: Diagnosing and Mitigating Idiosyncratic Biases in Preference Modelscited by 13
  9. 2025Environment Scaling for Interactive Agentic Experience Collection: A Surveycited by 13
  10. 2026Real-Time Aligned Reward Model beyond Semanticscited by 13
  11. 2025Bradley-Terry and Multi-Objective Reward Modeling Are Complementarycited by 11
  12. 2026Reward Modeling from Natural Language Human Feedbackcited by 11
  13. 2026Adversarial Reward Auditing for Active Detection and Mitigation of Reward Hackingcited by 11
  14. 2026Toward Robust LLM-Based Judges: Taxonomic Bias Evaluation and Debiasing Optimizationcited by 9
  15. 2025Bias Fitting to Mitigate Length Bias of Reward Model in RLHFcited by 7
  16. 2025Inverse Reinforcement Learning Meets Large Language Model Post-Training: Basics, Advances, and Opportunitiescited by 7
  17. 2026Tackling Length Inflation Without Trade-offs: Group Relative Reward Rescaling for Reinforcement Learningcited by 7
  18. 2025Two Minds Better Than One: Collaborative Reward Modeling for LLM Alignmentcited by 6
  19. 2025Preference Learning for AI Alignment: a Causal Perspectivecited by 6
  20. 2025Activation Reward Models for Few-Shot Model Alignmentcited by 6
  21. 2025APLOT: Robust Reward Modeling via Adaptive Preference Learning with Optimal Transportcited by 6
  22. 2025Rectifying Shortcut Behaviors in Preference-based Reward Learningcited by 6
  23. 2025Mitigating Length Bias in RLHF through a Causal Lenscited by 6
  24. 2026Uncertainty-Aware Reward Modeling for Stable RLHFcited by 6
  25. 2025Information-Theoretic Reward Decomposition for Generalizable RLHFcited by 5
  26. 2025Toward Evaluative Thinking: Meta Policy Optimization with Evolving Reward Modelscited by 5
  27. 2025Learning a Pessimistic Reward Model in RLHFcited by 5
  28. 2025CoLD: Counterfactually-Guided Length Debiasing for Process Reward Models in Mathematical Reasoningcited by 5
  29. 2025Causal Reward Adjustment: Mitigating Reward Hacking in External Reasoning via Backdoor Correctioncited by 5
  30. 2025Information-Theoretic Reward Modeling for Stable RLHF: Detecting and Mitigating Reward Hackingcited by 5
  31. 2026Spurious Correlation Learning in Preference Optimization: Mechanisms, Consequences, and Mitigation via Tie Trainingcited by 5
  32. 2025Fixing the Broken Compass: Diagnosing and Improving Inference-Time Reward Modelingcited by 4
  33. 2025Energy-Based Reward Models for Robust Language Model Alignmentcited by 4
  34. 2025Putting on the Thinking Hats: A Survey on Chain of Thought Fine-tuning from the Perspective of Human Reasoning Mechanismcited by 4
  35. 2026Automatically Finding Reward Model Biasescited by 4
  36. 2026SAIL: Self-Amplified Iterative Learning for Diffusion Model Alignment with Minimal Human Feedbackcited by 3
  37. 2026One Bias After Another: Mechanistic Reward Shaping and Persistent Biases in Language Reward Modelscited by 3
  38. 2026C2: Scalable Rubric-Augmented Reward Modeling from Binary Preferencescited by 3

50 most cited of 76 All 76 (JSON)

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  1. 2025Beyond Reward Hacking: Causal Rewards for Large Language Model Alignment
  2. 2025Teach a Reward Model to Correct Itself: Reward Guided Adversarial Failure Discovery for Robust Reward Modeling
  3. 2026RM-Distiller: Exploiting Generative LLM for Reward Model Distillation
  4. 2024Reward-Augmented Data Enhances Direct Preference Alignment of LLMs
  5. 2024Elephant in the Room: Unveiling the Impact of Reward Model Quality in Alignment
  6. 2026RMGAP: Benchmarking the Generalization of Reward Models across Diverse Preferences
  7. 2026VRM: Teaching Reward Models to Understand Authentic Human Preferences
  8. 2025LongRM: Revealing and Unlocking the Context Boundary of Reward Modeling