ThinkRouter: Efficient Reasoning via Routing Thinking between Latent and Discrete Spaces

Fuente: arXiv
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Hauptverfasser: Xu, Xin, Yu, Tong, Chen, Xiang, Wang, Haoliang, McAuley, Julian, Mitra, Saayan
Format: Preprint
Veröffentlicht: 2026
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author Xu, Xin
Yu, Tong
Chen, Xiang
Wang, Haoliang
McAuley, Julian
Mitra, Saayan
author_facet Xu, Xin
Yu, Tong
Chen, Xiang
Wang, Haoliang
McAuley, Julian
Mitra, Saayan
contents Recent work explores latent reasoning to improve reasoning efficiency by replacing explicit reasoning trajectories with continuous representations in a latent space, yet its effectiveness varies across settings. Analysis of model confidence dynamics under latent reasoning reveals that thinking trajectories ending in incorrect answers contain fewer low-confidence steps than those ending in correct answers. Meanwhile, we suggest that soft embeddings aggregated by multiple low-confidence thinking alternatives may introduce and propagate noise, leading to high confidence in unreliable reasoning trajectories. Motivated by these observations, ThinkRouter, an inference-time confidence-aware routing mechanism is proposed to avoid high confidence and noise for efficient reasoning. ThinkRouter routes thinking to the discrete token space when model confidence is low, and to the latent space otherwise. Extensive experiments on STEM reasoning and coding benchmarks across diverse large reasoning models demonstrate that ThinkRouter outperforms explicit CoT, random routing, and latent reasoning baselines in terms of accuracy, achieving an average improvement of 19.70 points in Pass@1, while reducing generation length by up to 15.55%. Further comprehensive analysis reveals that ThinkRouter can calibrate errors arising from explicit CoT and latent reasoning, and accelerates end-of-thinking token generation by globally lowering model confidence.
format Preprint
id arxiv_https___arxiv_org_abs_2602_11683
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle ThinkRouter: Efficient Reasoning via Routing Thinking between Latent and Discrete Spaces
Xu, Xin
Yu, Tong
Chen, Xiang
Wang, Haoliang
McAuley, Julian
Mitra, Saayan
Artificial Intelligence
Computation and Language
Machine Learning
Recent work explores latent reasoning to improve reasoning efficiency by replacing explicit reasoning trajectories with continuous representations in a latent space, yet its effectiveness varies across settings. Analysis of model confidence dynamics under latent reasoning reveals that thinking trajectories ending in incorrect answers contain fewer low-confidence steps than those ending in correct answers. Meanwhile, we suggest that soft embeddings aggregated by multiple low-confidence thinking alternatives may introduce and propagate noise, leading to high confidence in unreliable reasoning trajectories. Motivated by these observations, ThinkRouter, an inference-time confidence-aware routing mechanism is proposed to avoid high confidence and noise for efficient reasoning. ThinkRouter routes thinking to the discrete token space when model confidence is low, and to the latent space otherwise. Extensive experiments on STEM reasoning and coding benchmarks across diverse large reasoning models demonstrate that ThinkRouter outperforms explicit CoT, random routing, and latent reasoning baselines in terms of accuracy, achieving an average improvement of 19.70 points in Pass@1, while reducing generation length by up to 15.55%. Further comprehensive analysis reveals that ThinkRouter can calibrate errors arising from explicit CoT and latent reasoning, and accelerates end-of-thinking token generation by globally lowering model confidence.
title ThinkRouter: Efficient Reasoning via Routing Thinking between Latent and Discrete Spaces
topic Artificial Intelligence
Computation and Language
Machine Learning
url https://arxiv.org/abs/2602.11683