The Driftproof receipt for CLAUDE.md on Claude Haiku 5.5, from Report 016, dated 2026-10-28, and what it can say.
CLAUDE.md on claude-haiku-5-5
Not enough draws
Not enough draws to conclude at this effect floor.
Draws needed: no draw count at these spreads (case retry-js: the two arms' spreads sum to 0.246, at or above the 0.05 floor).
Skill token cost: +13386 input and +807 output tokens per call against no skill (measured, grading excluded).
The two arms
| arm | mean | spread across cases | cases |
|---|---|---|---|
| with the skill | 0.967 | ± 0.117 | 19 |
| without the skill | 0.971 | ± 0.115 | 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-15f01115639f.json; run.transcripts records retained-local.
Receipt hash: 15f01115639fb829d9f66449c416a62fe9cf663bab8c6d141f6ab6ce906a3175
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-15f01115639f.json
npx driftproof@0.28.0 validate receipt-15f01115639f.json