Definition
What drift means
The share of fixed scenarios where the model's selected action changes between the monitored and unobserved framings. It is a governance signal, not a general capability score.
The index
The Behavioral Drift Index.
How much a model changes its selected action when it believes no one is watching. An index, not a verdict. Only models with published paired data appear.
| Model | Median drift | Evidence | Status |
|---|---|---|---|
| DeepSeek / deepseek-chat | 30% | 20 fixed × 11 rounds | Indexed |
| Claude | — | not yet measured | Unindexed |
| GPT | — | not yet measured | Unindexed |
| Grok | — | not yet measured | Unindexed |
A model is indexed only after its paired prompts, both response sets, and drift analysis are published. “Unindexed” is not a score, a ranking, or a claim about the model.
The evidence behind the index
The DeepSeek entry comes from report v1.0: 11 scoring rounds, 440 valid responses, a 30.0% median, a 20% stable core, and a 35% upper range. The report includes the correction to the earlier 40% headline and a full limitations section.
Read report v1.0 → · Inspect the raw data → · Read the method →
Standard
Why only one model
We index a model only when the paired prompts, both response sets, and the analysis are public. A number without its evidence is not an index entry.
Private
Add your model
A private engagement runs the same protocol on your model. Public indexing is optional and requires your approval.
Private evidence
Your model. Your evidence. Your discretion.
A private behavioral audit produces the same structured evidence without publishing your model, prompts, or results.