Which nonparametric test is a counterpart to a one-way ANOVA for repeated measures?

The Friedman Test serves as the nonparametric equivalent of a one-way ANOVA for repeated measures because it is specifically designed for situations where the same subjects are measured multiple times under different conditions or at different time points. Like the one-way ANOVA, the Friedman Test tests for differences in distributions among three or more related groups, but it does not assume a normal distribution of the data, making it suitable for non-normally distributed samples.

In contrast, the Wilcoxon Signed Rank Test is utilized for comparing two related samples rather than multiple groups, thereby limiting its application in this context. The Mann Whitney U Test is used for independent samples, focusing on differences between two unrelated groups and not addressing repeated measures, while the Z Test is intended for comparing means in normally distributed data with known variance, which does not align with the requirements for analyzing repeated measures within a single sample. Thus, the Friedman Test is the appropriate choice for a nonparametric analysis similar to one-way ANOVA for repeated measures.