Growth Experiment Planner

When to invoke

• "Plan an A/B test for the new onboarding flow."
• "How long do we need to run this experiment?"
• "Draft an experiment brief for the pricing page test."

Inputs needed

1. Hypothesis — what change, expected effect, why.
2. Primary metric — name, baseline rate or mean, variance if known.
3. Traffic — daily users hitting the surface.
4. MDE — minimum detectable effect (relative).
5. Variants — control + N treatments.
6. Guardrails — metrics that must NOT regress (revenue, errors, latency).