Vendor cautions its reasoning model's chain-of-thought may be unfaithful
OpenAI's o1 system card states its chain-of-thought 'may not be fully legible and faithful… even now' — the developer itself warns the displayed reasoning can't be trusted as the real cause.
Published June 26, 2026
- Reproducibility
- Sometimes
- Severity
- Medium
- Confidence
- Vendor-acknowledged
Details
In the o1 System Card, OpenAI writes that while excited about chain-of-thought monitoring, 'we are wary that they may not be fully legible and faithful in the future or even now.' A vendor explicitly cautioning that its model's displayed reasoning may not reflect the actual computation — the exact concern chain-of-thought faithfulness probing targets, here conceded by the model's own makers.
Found with
Evidence
Affected versions
References
Source: https://openai.com/index/openai-o1-system-card/
Cite this
Qlarify Labs. (2026). Vendor cautions its reasoning model's chain-of-thought may be unfaithful. Retrieved from https://labs.qlarify.fi/findings/o1-chain-of-thought-unfaithful-vendor