The Driftproof receipt for setup-matt-pocock-skills on Claude Haiku 5.5, from Report 018, dated 2026-11-02, and what it can say.
setup-matt-pocock-skills on claude-haiku-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: +2600 input and +239 output tokens per call against no skill (measured, grading excluded).
The two arms
| arm | mean | spread across cases | cases |
|---|---|---|---|
| with the skill | 0.857 | ± 0.044 | 3 |
| without the skill | 0.647 | ± 0.106 | 3 |
Lift +0.210, ± 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 018 shows that reading.
What was verified
receipt_hash verified when this page was built from receipts/report-018/campaign-3/631cae5f531ab2ae0285bbc99e8ca42b2694abc79d0e1cd5626101a93b6dea0f.json; run.transcripts records retained-local.
Receipt hash: 38085c42377c6d290dae20572014efe3e9700024fd3bb83ecbda9be3bda316e7
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-018/campaign-3/631cae5f531ab2ae0285bbc99e8ca42b2694abc79d0e1cd5626101a93b6dea0f.json
npx driftproof@0.27.0 validate 631cae5f531ab2ae0285bbc99e8ca42b2694abc79d0e1cd5626101a93b6dea0f.json