Bayesian vs Frequentist A/B Testing: Which Should You Use?
· 4 min read
Every major A/B testing platform is now wrestling with the same question: Bayesian or frequentist?
Optimizely built their original tool on frequentist statistics. Then switched to "Stats Accelerator" (Bayesian). VWO calls their approach "SmartStats" (also Bayesian). Statsig uses frequentist for feature flags, Bayesian for experiments. The research teams at Microsoft and Netflix have published papers on both.
Here's the practical guide to what actually matters for your team.