The Driftproof receipt for design-mobile-apps on Claude Opus 5.5, dated 2026-10-18, and what it can say.
design-mobile-apps on claude-opus-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.
The two arms
| arm | mean | spread across cases | cases |
|---|---|---|---|
| with the skill | 0.896 | ± 0.094 | 3 |
| without the skill | 0.789 | ± 0.102 | 3 |
Lift +0.107, ± 0.138. 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/skill-measurements/published/ed4243f2bd1abef427c28306fe5357c9667735675daa28d6ac6b49089839fed8.json; run.transcripts records retained-local.
Receipt hash: 9f61b33fdfd72f62ba2eca30e2cc4dd84191f0abdab6d47d4f64f9319b8b7056
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/skill-measurements/published/ed4243f2bd1abef427c28306fe5357c9667735675daa28d6ac6b49089839fed8.json
npx driftproof@0.22.4 validate ed4243f2bd1abef427c28306fe5357c9667735675daa28d6ac6b49089839fed8.json