How do A/B tests work?

A look inside one of the most powerful tools of the tech trade

In a nutshell: A/B testing is all about studying causality by creating believable clones — two identical items (or, more typically, two statistically identical groups) — and then seeing the effects of treating them differently.

When I say two identical items, I mean even more identical than this. The key is to find “believable clones” …