Guided by Gut: Efficient Test-Time Scaling with Reinforced Intrinsic Confidence

Amirhosein Ghasemabadi, Keith G. Mills, Baochun Li, Di Niu


Abstract
Test-Time Scaling (TTS) methods for enhancing Large Language Model (LLM) reasoning often incur substantial inference costs, due to reliance on long chain-of-thought (CoT) generation, self-consistency sampling methods, or searching under Process Reward Models (PRMs). This paper introduces Guided by Gut (GG), an efficient self-guided TTS framework that enables LLMs to perform step-by-step reasoning at a low cost, without any reward models or verifiers. GG performs a lightweight tree search guided solely by intrinsic confidence signals of the LLM at each reasoning step and improves the reliability of such internal confidence signals by reinforcement learning. Empirical evaluations on challenging mathematical reasoning benchmarks demonstrate that GG enables smaller models (e.g., 1.5B-7B parameters) to achieve accuracy matching or surpassing significantly larger models (e.g., 32B–70B parameters), while reducing GPU memory usage by up to 10×. Compared to TTS with PRMs, GG achieves comparable accuracy with 8× faster inference speeds and 4–5× lower memory usage. Additionally, GG reduces KV cache memory usage by approximately 50% compared to Best-of-N sampling, facilitating more efficient and practical deployment of TTS techniques.
Anthology ID:
2026.acl-long.739
Volume:
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
ACL
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Publisher:
Association for Computational Linguistics
Note:
Pages:
16251–16265
Language:
URL:
https://preview.aclanthology.org/ingest-acl/2026.acl-long.739/
DOI:
Bibkey:
Cite (ACL):
Amirhosein Ghasemabadi, Keith G. Mills, Baochun Li, and Di Niu. 2026. Guided by Gut: Efficient Test-Time Scaling with Reinforced Intrinsic Confidence. In Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 16251–16265, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
Guided by Gut: Efficient Test-Time Scaling with Reinforced Intrinsic Confidence (Ghasemabadi et al., ACL 2026)
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https://preview.aclanthology.org/ingest-acl/2026.acl-long.739.pdf
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