Stop A/B Tests Early: The Complete Guide to Sequential Testing (mSPRT) in Python

Fixed-horizon A/B tests are slow and prone to false positives when you peek at data. Sequential testing with mSPRT enables anytime-valid inference, letting teams monitor experiments continuously and stop early without inflating Type I errors. Techniques like linearization and guardrails handle ratio metrics and outliers, ensuring fast, reliable, and statistically rigorous B2C decision-making.