The nonparametric tests for two related samples allow you to test for differences between paired scores when you cannot (or would rather not) make the assumptions required by the paired-samples t test. Procedures are available for testing nominal, ordinal, or scale variables.

The Wilcoxon signed-ranks method tests the null hypothesis that two related medians are the same. This test allows you to compare a single median against a known value or paired medians from the same (or matched) sample.

The McNemar method tests the null hypothesis that binary responses are unchanged. As with the Wilcoxon test, the data may be from a single sample measured twice or from two matched samples. The McNemar test is particularly appropriate with nominal or ordinal test variables.