Didi Chuxing is considering a new in-app coupon banner on the Didi Rider home screen to increase first ride booking among newly registered users. The Growth team wants a statistically sound A/B test design before launch.
Design the experiment and evaluate whether the proposed sample size is sufficient. Then, using pilot results, determine whether the treatment meaningfully improves conversion.
Baseline first-ride booking conversion for new users over 7 days is estimated at 18.0%. Product wants to detect at least a 1.5 percentage point absolute lift. Traffic is split 50/50 between control and treatment for 14 days.
| Metric | Value |
|---|---|
| Baseline conversion rate | 18.0% |
| Minimum detectable effect | 1.5 percentage points |
| Significance level | 0.05 |
| Power | 80% |
| Planned users per group | 18,000 |
| Pilot control users | 18,000 |
| Pilot treatment users | 18,000 |
| Pilot control converters | 3,240 |
| Pilot treatment converters | 3,582 |