FA-74500 / Experiment statistics / Member archive
Per-arm sample size for conversion tests: Alpha is not split across tails · case 05
Planned sample sizes are too small for the two-sided test that is actually run.
Case contract
p2 = p_base (1 + mde) when relative else p_base + mde; both rates must lie in (0, 1) and differ (else None). n per arm = ceil((z_{1-alpha/2} + z_power)^2 (p1(1-p1) + p2(1-p2)) / (p2 - p1)^2) using statistics.NormalDist quantiles.
Why this case matters
Underpowered experiments waste traffic; overestimates delay launches.
One recorded failure
Sample boundary fixtureThis sample comes from the broken implementation of a controlled reproducer.
| Boundary fixture | Actual | Expected | Outcome |
|---|---|---|---|
| ten percent relative lift on five percent | 24601 | 31231 | Failed |
MEMBER ARCHIVE
The complete case is available to members.
This record includes three runnable implementations, regression fixtures, execution results, and source hashes.
Member access is invitation-based. Sign in with your invited account to inspect the sources.
Sign in to the archive ↗