What is a confidence level?
A confidence level is the level of probability that a result or hypothesis is statistically significant. For example in a classic A/B marketing test the hypothesis is basically that one version provides a better user response than the other. Our calculators will work out whether given the size of difference in response and the number of people in the market test, the sample size, the confidence level. A 95% confidence level means that there is 95% probablity if the test was repeated the result would be the same.
