Calculate the Chi-Square Statistic of Conversions
Chi Square Calculator
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Frequently Asked Questions
What Is a Chi-Square Statistic?
A Chi-Square (χ2) statistic is a measurement of distance between expected and actual counts for categorical data, like conversions in A/B testing.
In A/B testing, your visitors are categorized in two ways:
- Conversion Status: Converted
- Not Converted Recipe Applied: Control vs. Variant 1 vs. Variant 2
We use the Chi-Square Testing Calculator to determine if the applied recipe influences conversion status by measuring the distance of the actual counts from those that we would expect if they were not related. Specifically, it tests whether each recipe affects conversion differently than each of the others.
What Do I Do with a Significant Test?
A significant Chi-Square Test tells you that a statistically significant difference exists, but not which difference or differences caused significance. The next step after identifying a significant Chi-Square Test is to test the difference between all pairs of treatments (e.g. Variant 1 vs. Control) using our Statistical Significance Calculator.
Even if you can visually see what is likely to be a significant difference, it is important to run all tests to make sure no statistically significant differences are missed.
What Does Confidence Level Mean for My Business?
If you are 95% confident that at least one recipe is different than another, there is a 1-in-20 chance that the patterns are all the same. If you roll out the statistically best recipe after doing your pair-wise tests, you will have a 1-in-20 chance of not seeing that lift.
DISCOVER OTHER HELPFUL RESOURCES
Statistical Significance Calculator
The go-to A/B Test calculator, if you know your KPI conversion rate and sample size, you have everything you need.
Sample Size Calculator
Calculate the sample size necessary to reach 95% confidence with your current conversion rate and desired lift.
Z-Score to Confidence Calculator
Using your standardized z-score, you can use this calculator to convert that score to a confidence level for either one-sided or two-sided A/B tests.