What it is: a measure of how unlikely a test result is due to chance. The more statistical significance, the more reliable the result.

What it's not: a way to say how meaningful or important results are-- Significance here refers to an actual mathematical percentage, not the qualitative significance of the result.

Why we care: Statistical significance helps to determine whether a result is really a win, or if the error margin is too large to declare a win or a loss. Stuck on whether your results are significant or not? Try our statistical significance calculator.

This post is part of an ongoing Clickipedia series, defining all the terms you need to know for conversion rate optimization. Keep checking back each week to learn more, and don’t forget to check out the whole series.