In statistics, you have statistical tests called ANOVA or Analysis of Variance. There is One-Way ANOVA and Two-Way ANOVA. You can only use One-Way ANOVA when you are testing only one dependent variable against at least two independent variables. For example, you want to find the statistics of the adsorption capacity with respect to two of its factors: pH and temperature. In this test, you only get the variance once and it is based on the F table of distibution. The other name for this, is actually the F-test.
