If you have nominal variables there is no ordering or distance function. So how could you define any of the summary statistics that you mention? I don't think you can. Quartiles and range at least require ordering and means and variance require numerical data. I think bar graphs and pie chart are typical examples of the proper ways to summarize qualitative variables that are not ordinal.
Michael R. Chernick
- 43.2k
- 28
- 85
- 159