Multiple Sample Tests
Studies that refer to repeated measurements or pairs of subjects typically collect at least two sets of scores. Studies that refer to specific subgroups in the population also collect two or more samples of data. Once you have determined that the design uses two or more samples or "groups", then you must determine how many samples or groups are in the design. Studies that are limited to two groups use either the chi-square statistic, Mann-Whitney U, Wilcoxon T, independent means t test, or the dependent means t test.

If you have three or more groups in the design, the chi-square statistic, Kruskal-Wallis H Test, Friedman ANOVA for ranks, One-way Between-Groups ANOVA, Simple Repeated Measures ANOVA, Factorial ANOVA, and Mixed Factorial ANOVA depending on the nature of the relationship between groups. Some of these tests are designed for dependent or correlated samples/groups and some are designed for samples/groups that are completely independent.