ThoughtProbe: Classifier-Guided LLM Thought Space Exploration via Probing Representations

Fuente: arXiv
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Main Authors: Wang, Zijian, Xu, Chang
Format: Preprint
Published: 2025
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author Wang, Zijian
Xu, Chang
author_facet Wang, Zijian
Xu, Chang
contents This paper introduces ThoughtProbe, a novel inference time framework that leverages the hidden reasoning features of Large Language Models (LLMs) to improve their reasoning performance. Unlike previous works that manipulate the hidden representations to steer LLM generation, we harness them as discriminative signals to guide the tree structured response space exploration. In each node expansion, a classifier serves as a scoring and ranking mechanism that efficiently allocates computational resources by prioritizing higher score candidates for continuation. After completing the tree expansion, we collect answers from all branches to form a candidate answer pool. We then propose a branch aggregation method that marginalizes over all supporting branches by aggregating their CoT scores, thereby identifying the optimal answer from the pool. Experimental results show that our framework's comprehensive exploration not only covers valid reasoning chains but also effectively identifies them, achieving significant improvements across multiple arithmetic reasoning benchmarks.
format Preprint
id arxiv_https___arxiv_org_abs_2510_27355
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle ThoughtProbe: Classifier-Guided LLM Thought Space Exploration via Probing Representations
Wang, Zijian
Xu, Chang
Computation and Language
This paper introduces ThoughtProbe, a novel inference time framework that leverages the hidden reasoning features of Large Language Models (LLMs) to improve their reasoning performance. Unlike previous works that manipulate the hidden representations to steer LLM generation, we harness them as discriminative signals to guide the tree structured response space exploration. In each node expansion, a classifier serves as a scoring and ranking mechanism that efficiently allocates computational resources by prioritizing higher score candidates for continuation. After completing the tree expansion, we collect answers from all branches to form a candidate answer pool. We then propose a branch aggregation method that marginalizes over all supporting branches by aggregating their CoT scores, thereby identifying the optimal answer from the pool. Experimental results show that our framework's comprehensive exploration not only covers valid reasoning chains but also effectively identifies them, achieving significant improvements across multiple arithmetic reasoning benchmarks.
title ThoughtProbe: Classifier-Guided LLM Thought Space Exploration via Probing Representations
topic Computation and Language
url https://arxiv.org/abs/2510.27355