The Driftproof receipt for setup-matt-pocock-skills on Claude Opus 5.5, dated 2026-10-18, and what it can say.
setup-matt-pocock-skills 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 | 0.897 | ± 0.179 | 3 |
| without the skill | 0.773 | ± 0.053 | 3 |
Lift +0.123, ± 0.187. 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/178358a690b1878459d930c59acd931b5841521d7d88bb02ae11611c56e9ea03.json; run.transcripts records retained-local.
Receipt hash: a6387128d860520217327680b2b121a6002ff72a6eda508807526fb9cfbf39a9
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/178358a690b1878459d930c59acd931b5841521d7d88bb02ae11611c56e9ea03.json
npx driftproof@0.22.4 validate 178358a690b1878459d930c59acd931b5841521d7d88bb02ae11611c56e9ea03.json