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Main Authors: Hu, Zhiyuan, Wang, Yucheng, He, Yufei, Wu, Jiaying, Zhao, Yilun, Ng, See-Kiong, Breazeal, Cynthia, Luu, Anh Tuan, Park, Hae Won, Hooi, Bryan
Format: Preprint
Published: 2026
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Online Access:https://arxiv.org/abs/2601.08763
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author Hu, Zhiyuan
Wang, Yucheng
He, Yufei
Wu, Jiaying
Zhao, Yilun
Ng, See-Kiong
Breazeal, Cynthia
Luu, Anh Tuan
Park, Hae Won
Hooi, Bryan
author_facet Hu, Zhiyuan
Wang, Yucheng
He, Yufei
Wu, Jiaying
Zhao, Yilun
Ng, See-Kiong
Breazeal, Cynthia
Luu, Anh Tuan
Park, Hae Won
Hooi, Bryan
contents Reinforcement learning (RL) has become a central paradigm for post-training large language models (LLMs), particularly for complex reasoning tasks, yet it often suffers from exploration collapse: policies prematurely concentrate on a small set of dominant reasoning patterns, improving pass@1 while limiting rollout-level diversity and gains in pass@k. We argue that this failure stems from regularizing local token behavior rather than diversity over sets of solutions. To address this, we propose Uniqueness-Aware Reinforcement Learning, a rollout-level objective that explicitly rewards correct solutions that exhibit rare high-level strategies. Our method uses an LLM-based judge to cluster rollouts for the same problem according to their high-level solution strategies, ignoring superficial variations, and reweights policy advantages inversely with cluster size. As a result, correct but novel strategies receive higher rewards than redundant ones. Across mathematics, physics, and medical reasoning benchmarks, our approach consistently improves pass@$k$ across large sampling budgets and increases the area under the pass@$k$ curve (AUC@$K$) without sacrificing pass@1, while sustaining exploration and uncovering more diverse solution strategies at scale.
format Preprint
id arxiv_https___arxiv_org_abs_2601_08763
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Rewarding the Rare: Uniqueness-Aware RL for Creative Problem Solving in LLMs
Hu, Zhiyuan
Wang, Yucheng
He, Yufei
Wu, Jiaying
Zhao, Yilun
Ng, See-Kiong
Breazeal, Cynthia
Luu, Anh Tuan
Park, Hae Won
Hooi, Bryan
Machine Learning
Computation and Language
Reinforcement learning (RL) has become a central paradigm for post-training large language models (LLMs), particularly for complex reasoning tasks, yet it often suffers from exploration collapse: policies prematurely concentrate on a small set of dominant reasoning patterns, improving pass@1 while limiting rollout-level diversity and gains in pass@k. We argue that this failure stems from regularizing local token behavior rather than diversity over sets of solutions. To address this, we propose Uniqueness-Aware Reinforcement Learning, a rollout-level objective that explicitly rewards correct solutions that exhibit rare high-level strategies. Our method uses an LLM-based judge to cluster rollouts for the same problem according to their high-level solution strategies, ignoring superficial variations, and reweights policy advantages inversely with cluster size. As a result, correct but novel strategies receive higher rewards than redundant ones. Across mathematics, physics, and medical reasoning benchmarks, our approach consistently improves pass@$k$ across large sampling budgets and increases the area under the pass@$k$ curve (AUC@$K$) without sacrificing pass@1, while sustaining exploration and uncovering more diverse solution strategies at scale.
title Rewarding the Rare: Uniqueness-Aware RL for Creative Problem Solving in LLMs
topic Machine Learning
Computation and Language
url https://arxiv.org/abs/2601.08763