Section author: Jonas Rafi

ANOVA: Repeated Measures

How to perform a repeated measures ANOVA in jamovi:
  1. You need one continuous continuous outcome variable for each measurement occasion.
    A correct setup should look similar to this:

    data_format_anova_repeated


  2. Select Analyses → ANOVA → Repeated Measures ANOVA.

    select_anova_repeated


  3. In the box Repeated Measures Factors: write the name of your outcome variable (e.g. My_scale) and name the levels for each measurement occasion (e.g. Pre, Post and 12 month follow-up). The images below shows the box with default values (left) and when the values has been set (right).

    add_var_anova_repeated_naming_1 → add_var_anova_repeated_naming_2


  4. Drag and drop your outcome variables to their respective cells in Repeated Measures Cells.

    add_var_anova_repeated


  5. To test the equality of the variance with the Levene test, open the Assumption Checks drop-down menu and set the Homogeneity test tick box. It is also a good idea to check that the variances at the different steps of the repetition factor are the same (Sphericity). To do so, open the Assumption Checks drop-down menu and set the Sphericity tests tick box.

  6. The results are shown in the right panel:

    output_anova_repeated


Further help from the community resources

A more comprehensive introduction into this statistical method is provided by this video by Barton Poulson.
For those, aiming to stretch even further to an in-depth introduction, you can read the respective section in the “Learning statistics with jamovi” web documentation or chapter 13.7 of the e-book by Danielle J. Navarro and David R. Foxcroft.