Minimum detectable effect (MDE)
The smallest change in a metric that a test is designed to detect reliably.
If your MDE is 5%, the test is sized to catch a lift of 5% or more. Smaller real effects may still exist, but the test is not large enough to tell them apart from noise.
MDE and sample size trade off against each other. Halving the effect you want to detect roughly quadruples the visitors you need. Lower-traffic stores should set a larger MDE and test bolder changes.
Put it to the test on your store
Test prices, themes, pages, shipping and checkout on Shopify, then ship the winning variant.
