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Glossary
Relative Lift
The percentage improvement of one variant over another.
What is Relative Lift?
Relative lift is the percentage improvement of Variant B over Variant A, calculated as:
Relative Lift = (B - A) / A × 100%
For example, if A converts at 10% and B converts at 12%, the relative lift is +20%.
Relative vs Absolute Lift
- Relative lift: +20% (percentage improvement)
- Absolute lift: +2 percentage points (12% - 10%)
Both are useful. Relative lift helps compare across different baseline rates. Absolute lift shows the actual change in conversion.
Interpreting Lift
| Lift | Typical Impact |
|---|---|
| < 5% | Small improvement — needs large sample to detect |
| 5-15% | Moderate improvement — typical for good tests |
| 15-30% | Strong improvement — significant change |
| > 30% | Very large — verify it's real, not a bug |