A repeated measures ANOVA is also referred to as a within-subjects ANOVA or ANOVA for correlated samples. The repeated-measures ANOVA is used for analyzing data where same subjects are measured more than once.

The “within-subjects” term means that the same individuals are measured on the same outcome variable under different time points or conditions. Repeated measures ANOVA is the equivalent of the one-way ANOVA, but for related, not independent groups, and is the extension of the dependent t-test. This test is also referred to as a within-subjects ANOVA or ANOVA with repeated measures. A typical guideline to determine whether the repeated measures ANOVA is the right test is to answer the following three questions: Is there a direct relationship between each pair of observations, e.g., before vs. after scores on the same subject?