Overview for Mood’s Median Test

Use Mood’s Median Test when you have one categorical factor and a continuous response, and you are not confident that the data for all of the groups have similarly shaped distributions. Using this analysis, you can do the following:
  • Determine whether the medians of two or more groups differ.
  • Calculate a range of values that is likely to include the difference between population medians.

For example, a researcher wants to determine whether the presentation method that a teacher uses affects students' comprehension of the lecture. The researcher selects 149 students and randomly assigns them to lectures that use one of three different presentation methods: text descriptions, photographs, or cartoons.

Where to find this analysis

To perform Mood's median test, choose Stat > Nonparametrics > Mood’s Median Test.

When to use an alternate analysis

  • If your data meet the following sample size guidelines, consider using One-Way ANOVA because it will perform very well with skewed and nonnormal distributions, and it has more power.
    • The data contain 2–9 groups and the sample size for each group is at least 15.
    • The data contain 10–12 groups and the sample size for each group is at least 20.
  • If the distributions of the groups do not include outliers, use Kruskal-Wallis Test because it has more power.
  • If you have a randomized block design and want to test the medians, use Friedman Test.