The Driftproof receipt for improve-codebase-architecture on Claude Opus 5.5, dated 2026-10-18, and what it can say.
improve-codebase-architecture 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 | 0.837 | ± 0.071 | 3 |
| without the skill | 0.735 | ± 0.118 | 3 |
Lift +0.102, ± 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/dd48f6ad46831a943dbf343b4f00a54df200f1ec07fe5f7c2db201abd622bd35.json; run.transcripts records retained-local.
Receipt hash: 7f25e71e3e4c42264e38229f75a799a7aa13bd09850a7813abc7d41fa2c17a53
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/dd48f6ad46831a943dbf343b4f00a54df200f1ec07fe5f7c2db201abd622bd35.json
npx driftproof@0.22.4 validate dd48f6ad46831a943dbf343b4f00a54df200f1ec07fe5f7c2db201abd622bd35.json