The Driftproof receipt for design-mobile-apps on Claude Sonnet 5.5, dated 2026-11-01, and what it can say.
design-mobile-apps on claude-sonnet-5-5
Passing
A case separated upward under the band rule. That is a separation detected under the rule, not proof that the skill moved the score.
Skill token cost: +2935 input and +48 output tokens per call against no skill (measured, grading excluded).
The two arms
| arm | mean | spread across cases | cases |
|---|---|---|---|
| with the skill | 0.823 | ± 0.112 | 3 |
| without the skill | 0.739 | ± 0.025 | 3 |
Lift +0.084, ± 0.115. 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.
This receipt also reads the skill against a same-length placebo. Report 017 shows that reading.
What was verified
receipt_hash verified when this page was built from receipts/report-017c/campaign-1/91292198c479ada88c866ab5038b12522204cbe9bf681e9a9a2f4d81ee628432.json; run.transcripts records retained-local.
Receipt hash: 9fa7bc62d8703ea066da8b40f0b3adc7c51a153f524155767b5c9e24f4042c1e
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-017c/campaign-1/91292198c479ada88c866ab5038b12522204cbe9bf681e9a9a2f4d81ee628432.json
npx driftproof@0.27.0 validate 91292198c479ada88c866ab5038b12522204cbe9bf681e9a9a2f4d81ee628432.json