To group modalities of a categorical variable together:
- In Multivariate analysis, choose the variable to explain and the explanatory variables.
- Click on the "+" button of the explanatory variable you want to group.
- Choose the new distribution you want for the modalities. If you choose to ignore a modality, the observations concerned will be removed from the model (you will loose statistical power).
- Click on "Confirm" to validate your choice, click on "Remove mapping" to reintegrate modalities as they were initially.