The Driftproof receipt for CLAUDE.md on Claude Sonnet 5.5, from Report 016, dated 2026-10-28, and what it can say.
CLAUDE.md on claude-sonnet-5-5
More cases needed
More cases, not more draws, are needed to conclude at this effect floor.
Draws needed: none is expected to bring this band under the floor (the comparison band over the 19 cases is plus or minus 0.081; with each case's draw-to-draw spread taken out it is plus or minus 0.081, still at or above the 0.05 floor).
Skill token cost: +2105 input and -51 output tokens per call against no skill (measured, grading excluded).
The two arms
| arm | mean | spread across cases | cases |
|---|---|---|---|
| with the skill | 0.987 | ± 0.057 | 19 |
| without the skill | 0.987 | ± 0.057 | 19 |
No lift is stated for a state that did not measure one. 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/report-016/receipt-abbbf0c5e42e.json; run.transcripts records retained-local.
Receipt hash: abbbf0c5e42ecbf92e392786e9aaa4b690f9714289f08be29347f6331af18fd4
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-016/receipt-abbbf0c5e42e.json
npx driftproof@0.28.0 validate receipt-abbbf0c5e42e.json