Product Management playbook/Module 6 · Evidence

Day 52 / 100 · Evidence · A/B testing basics

Let customers vote with their behaviour.

An A/B test shows two versions to similar groups at the same time. Randomisation is what lets you say the change caused the difference.

01 · Split

Randomly assign users to A (today) or B (the change).

02 · CHANGE ONE THING

So you know what caused any difference.

03 · MEASURE

The primary metric, plus guardrails.

04 · WAIT, THEN DECIDE

Run for the agreed time. No peeking early.

Version A

Control

  • What customers see today
  • The baseline you compare against

Version B

Variant

  • One deliberate change
  • Everything else identical

Randomise. Wait. Then decide.