Glossary · Reliability, calibration, and statistics
Beta-binomial posterior
A Bayesian model for a pass rate: a Beta(α, β) prior updated on s passes in n tasks gives a Beta(α + s, β + n − s) posterior, which answers release questions such as Pr[pass rate > 95%].
Also called: Beta-binomial model, Beta posterior
Defined in
Handbook · ValidationEstimands, pass rates, and intervalsWrite the estimand first, then report n, an honest interval and the right functional, from Wilson to pass^k to reweighted estimates.Related terms
- Wilson interval
- A confidence interval for a binomial proportion that behaves well near 0 and 1 and at small n. The default interval for pass rates.
- Rule of three
- After n independent trials with zero failures, a rough 95% upper bound on the failure probability is 3/n. Zero failures is not zero risk.
Where it comes up
- Decision claimsHandbook · Claim
- Rare-event assuranceHandbook · Validation
- Notation and formula cardHandbook · Reference