Monthly Archives: June 2018

Analysis of 115 A/B Tests: Average Lift is 4%, Most Lack Statistical Power

Observed Percent Change Significant

What can you learn from 115 publicly available A/B tests? Usually, not much, since in most cases you would be looking at case studies with very basic data about what was tested and the outcome of the A/B test. Confidence intervals, p-values and other measurements of uncertainty will often be missing, and when present they […] Read More…

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Confidence Intervals & P-values for Percent Change / Relative Difference

In many controlled experiments, including online controlled experiments (a.k.a. A/B tests) the result of interest and hence the inference made is about the relative difference between the control and treatment group. In A/B testing as part of conversion rate optimization and in marketing experiments in general we use the termĀ “percent lift” (“percentage lift”) while in […] Read More…

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