| title | Reliable Chain-of-Thought via Prefix Consistency |
|---|---|
| authors | Naoto Iwase, Yuki Ichihara, Mohammad Atif Quamar, Junpei Komiyama |
| date | 2026-05-08 |
| venue | arXiv (preprint, not peer reviewed) |
| id | arXiv:2605.07654 |
| affiliation | Mohamed Bin Zayed University of Artificial Intelligence |
| upvotes | 1 (Hugging Face Daily Papers, 2026-11-01) |
| links | abs pdf hf code |
| abstract | Large Language Models often improve accuracy on reasoning tasks by sampling multiple Chain-of-Thought (CoT) traces and aggregating them with majority voting (MV), a test-time technique called self-consistency. When we truncate a CoT partway through and regenerate the remainder, we observe that traces with correct answers reproduce their original answer more often than traces with wrong answers. We use this difference as a reliability signal, prefix consistency, that weights each candidate answer by how often it reappears under regeneration. It requires no access to token log-probabilities or self-rating prompts. Across five reasoning models and four math and science benchmarks, prefix consistency is the best correctness predictor in most settings, and reweighting votes by it reaches Standard MV plateau accuracy at up to 21x fewer tokens (median 4.6x). Our code is available at https://github.com/naoto-iwase/prefix-consistency. |
cite
@misc{iwase2026reliable,
title={Reliable Chain-of-Thought via Prefix Consistency},
author={Naoto Iwase and Yuki Ichihara and Mohammad Atif Quamar and Junpei Komiyama},
year={2026},
eprint={2605.07654},
archivePrefix={arXiv},
url={https://arxiv.org/abs/2605.07654}
}