Articles exploring test-duration through the lens of behavioral science and experimentation. Practical frameworks for growth leaders who measure in revenue, not vanity metrics.
3 articles
There's no single number. But there is a rigorous framework. Here's how to calculate exactly how long your A/B test needs to run — and why stopping early is the most expensive mistake in CRO.
Seven years running 100+ experiments taught me that test duration is the most violated rule in CRO. Here's the full framework — minimum days, sample size math, and when it's actually OK to stop early.
Learn how to calculate the right sample size and test duration for A/B tests. Understand regression to the mean, why peeking kills tests, and the magic number myth.