How Slow Devices Pollute Your A/B Tests (And How to Diagnose It)

When you run A/B tests, you most likely have your tool firing its script in one place and Google Analytics firing in another. Very rarely do both tools agree on how many people saw your test. This disagreement usually reads as a small, annoying thing you learn to ignore. Until it’s not small. Now you’re wondering: Which tool is right and how do I even begin to tell? Ryan Levander took the first pass at answering this in Why The Data Doesn’t Match Up When Analyzing Test Results . He argued that t