The Driftproof receipt for writing-plans on claude-fable-5, run on 2026-08-18, and what it can say.
writing-plans on claude-fable-5
Not measured
This receipt carries no verdict: it does not record that a model answered the run.
The two arms
| arm | mean | spread across cases | cases |
|---|---|---|---|
| with the skill | 0.831 | ± 0.092 | 7 |
| without the skill | 0.654 | ± 0.171 | 7 |
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-005/writing-plans__claude-fable-5.json; run.transcripts records retained-local.
Receipt hash: 1211b0126d5a241c20af8728dfe83c4b03040a2550918c4a9d9e4a8aba0551a4
Verify this receipt yourself
curl -fsSLO https://raw.githubusercontent.com/driftproofhq/driftproof/main/receipts/report-005/writing-plans__claude-fable-5.json
npx driftproof validate writing-plans__claude-fable-5.json