LLMs Knowingly Hide Their Mistakes

TL;DR: We prefill models with synthetic mistakes and then send a follow-up message. Models fail to disclose the mistake in 67% of cases. In 5% of cases, they notice the mistake in their chain-of-thought (CoT) but don't disclose it anyway. This is deception by omission.This means models cannot be relied upon to self-report their mistakes. Full paper: arXiv:2610.11351Trajectory viewer: lucas-florin.github.io/mistake-honesty-eval/IntroductionAs LLMs act as AI agents with little human oversight and,...