Think or Not? Exploring Thinking Efficiency in Large Reasoning Models via an Information-Theoretic Lens

Fuente: arXiv
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Main Authors: Yong, Xixian, Zhou, Xiao, Zhang, Yingying, Li, Jinlin, Zheng, Yefeng, Wu, Xian
Format: Preprint
Published: 2025
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author Yong, Xixian
Zhou, Xiao
Zhang, Yingying
Li, Jinlin
Zheng, Yefeng
Wu, Xian
author_facet Yong, Xixian
Zhou, Xiao
Zhang, Yingying
Li, Jinlin
Zheng, Yefeng
Wu, Xian
contents The recent rise of Large Reasoning Models (LRMs) has significantly improved multi-step reasoning performance, but often at the cost of generating excessively long reasoning chains. This paper revisits the efficiency of such reasoning processes through an information-theoretic lens, revealing a fundamental trade-off between reasoning length and semantic efficiency. We propose two metrics, InfoBias and InfoGain, to quantify divergence from ideal reasoning paths and stepwise information contribution, respectively. Empirical analyses show that longer reasoning chains tend to exhibit higher information bias and diminishing information gain, especially for incorrect answers. Motivated by these findings, we introduce an entropy-based Adaptive Think strategy that dynamically halts reasoning once confidence is sufficiently high, improving efficiency while maintaining competitive accuracy. Compared to the Vanilla Think approach (default mode), our strategy yields a 1.10% improvement in average accuracy and a 50.80% reduction in token usage on QwQ-32B across six benchmark tasks spanning diverse reasoning types and difficulty levels, demonstrating superior efficiency and reasoning performance. These results underscore the promise of entropy-based methods for enhancing both accuracy and cost-effiiciency in large language model deployment.
format Preprint
id arxiv_https___arxiv_org_abs_2505_18237
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Think or Not? Exploring Thinking Efficiency in Large Reasoning Models via an Information-Theoretic Lens
Yong, Xixian
Zhou, Xiao
Zhang, Yingying
Li, Jinlin
Zheng, Yefeng
Wu, Xian
Computation and Language
Artificial Intelligence
Information Theory
The recent rise of Large Reasoning Models (LRMs) has significantly improved multi-step reasoning performance, but often at the cost of generating excessively long reasoning chains. This paper revisits the efficiency of such reasoning processes through an information-theoretic lens, revealing a fundamental trade-off between reasoning length and semantic efficiency. We propose two metrics, InfoBias and InfoGain, to quantify divergence from ideal reasoning paths and stepwise information contribution, respectively. Empirical analyses show that longer reasoning chains tend to exhibit higher information bias and diminishing information gain, especially for incorrect answers. Motivated by these findings, we introduce an entropy-based Adaptive Think strategy that dynamically halts reasoning once confidence is sufficiently high, improving efficiency while maintaining competitive accuracy. Compared to the Vanilla Think approach (default mode), our strategy yields a 1.10% improvement in average accuracy and a 50.80% reduction in token usage on QwQ-32B across six benchmark tasks spanning diverse reasoning types and difficulty levels, demonstrating superior efficiency and reasoning performance. These results underscore the promise of entropy-based methods for enhancing both accuracy and cost-effiiciency in large language model deployment.
title Think or Not? Exploring Thinking Efficiency in Large Reasoning Models via an Information-Theoretic Lens
topic Computation and Language
Artificial Intelligence
Information Theory
url https://arxiv.org/abs/2505.18237