Friedman test

The Friedman test is an extension of the Wilcoxon signed-rank test and the nonparametric analog of one-way repeated-measures. Friedman tests the null hypothesis that k related variables come from the same population. For each case, the k variables are ranked from 1 to k. The test statistic is based on these ranks.

Does the public associate different amounts of prestige with a doctor, a lawyer, a police officer, and a teacher? Ten people are asked to rank these four occupations in order of prestige. Friedman's test indicates that the public does associate different amounts of prestige with these four professions.
Mean, standard deviation, minimum, maximum, number of nonmissing cases, and quartiles. Tests: Friedman.

Data considerations

Use numeric variables that can be ordered.
Nonparametric tests do not require assumptions about the shape of the underlying distribution. Use dependent, random samples.

Obtaining a Friedman test

This feature requires Statistics Base Edition.

  1. From the menus choose:

    Analyze > Group comparison - nonparametric > Friedman test

  2. Click Select variables under the Dependent variables section, select one or more numeric test variables, and then click OK.
  3. Optionally, expand the Additional settings menu and click the following:
    • Click Comparisons to specify options for multiple comparison tests.
    • Click Options to specify the confidence interval, significance level, case basis for analysis, and user-missing values settings.
  4. Click Run analysis.

This procedure pastes NPTESTS command syntax.