The Scenario
A fictional online bookstore has a cart abandonment email that sees a 14% open rate. The marketing team wants to lift it to 20%+ but has only run one prior test and it was inconclusive because the sample size was too small.
The Brief
Design a subject line A/B test that could actually be run and trusted. You can assume the list is 60,000 active subscribers and the email is triggered roughly 400 times per day.
Deliverables
- Two competing subject lines with a one-sentence hypothesis for each
- Sample size per variant and how many days the test needs to run, with your reasoning
- Primary metric, guardrail metrics, and the decision rule (what result would cause you to ship the winner vs. keep testing)
- One risk or confound you need to control for
Submission Guidance
Show your working on sample size. A test plan without a stopping rule is not a test plan.
Submit Your Work
Your submission is graded against the rubric on the right. If you pass, you get a public Badge URL you can share on LinkedIn. There is no draft save, so work offline first and paste your finished response here.