The Driftproof receipt for writing-plans on Claude Sonnet 4.6, from Report 001, dated 2026-07-28, and what it can say.
writing-plans on claude-sonnet-4-6
Not measured
This receipt carries no verdict: it does not record that a model answered the run.
Skill token cost: not measured.
The two arms
| arm | mean | spread across cases | cases |
|---|---|---|---|
| with the skill | 0.811 | ± 0.089 | 7 |
| without the skill | 0.576 | ± 0.230 | 7 |
No lift is stated for a state that did not measure one. A spread is the sample standard deviation of the per-case means: a descriptive spread with no coverage probability. The verdict above reads each case's two bands, not these aggregates.
What was verified
receipt_hash verified when this page was built from receipts/report-001/writing-plans__claude-sonnet-4-6.json; this receipt does not record run.transcripts.
Receipt hash: b69fdabff0784e1e8831dde83c3f0d8200c5d2ba8ada0a13fc3b62f194ce7e07
Check this file yourself
validate shows that this file is unchanged since it was sealed. It does not show who made it or who sealed it.
curl -fsSLO https://raw.githubusercontent.com/driftproofhq/driftproof/main/receipts/report-001/writing-plans__claude-sonnet-4-6.json
npx driftproof@0.28.0 validate writing-plans__claude-sonnet-4-6.json