[thewataccount]

I agree that it can be a difficult thing to analyze. There's also the Hawthorne Effect at play here too. But those are just confounding variables, they do not negate the fact that A/B tests are still "real science".

An A/B test just refers to observing how a dependent variable changes when an independent variable is in two different states, State A and State B.

Drug vs placebo - is an A/B test.