EZ Statistics is a web service with the goal of making statistical testing easy. It supports a range of the most commonly used parametric and non-parametric tests.

 What do you want to do?

   - Check if there is a difference between the means of samples


There are several tests and which one to use depends on the properties of your data and the setup of your study: Use the following tables to find out which test to use:
 
Parametric tests
Requires that the samples are normally distributed
Number of samples Variance? Dependency? Use the following test
1 (and a specified mean) - - T-test (single sample)
2 Equal Independent T-test (independent, equal variances)
2 Unequal Independent T-test (independent, unequal variances)
2 - Dependent T-test (paired)
3 or more Equal Independent One-way ANOVA

 
Non-parametric tests
Does not require that the samples are normally distributed
Number of samples Variance? Dependency? Use the following test
2 - Independent Wilcoxon Rank-Sum test
2 - Dependent Wilcoxon Signed-Ranks test
3 or more - Independent Kruskal-Wallis test