The Math Behind Good Decisions

Don't call a winner too early. A beginner-friendly guide to understanding the math behind your tests.

What is Statistical Significance?

It's the probability that your result isn't due to random chance. 95% significance = 95% confident the result is real, not luck.

Sample Size Matters

A 50% increase in conversions means nothing if only 10 people visited the page. Use an A/B test calculator to determine the required sample size before starting.

Avoiding False Positives

Never peek at your data on day two and stop the test. Weekly traffic fluctuations will trick you. Run tests for full 7-day cycles.