My purpose: When trying to find out which variables of a generic questionnaire data set will show striking differences across columns in crosstabs, I first do correlation tests (or dependence tests) across all pairs of variables (similar to this question).
Let's say that the dataset only consists of categorical (i.e. nominal) data and ordinal data (from Likert scales).
- For 1 nominal vs 1 nominal variable, I use the Fisher Exact Test or the Chi-Square Test of Independence.
- For 1 nominal vs 1 ordinal variable or vice-versa, I would like to do a non-parametric test, but which one should I use?
I thought about Kruskal-Wallis, point-biserial correlation coefficient or Eta squared test, but I cannot evaluate which makes most sense for finding differences across categories (in case the crosstab has categorical var as columns) or ordinal categories (in case the crosstab has a Likert scale as columns).
"Down-grading" the ordinal vars to categorical would be one obvious work-around, but I would prefer not to lose the ordinal information. Thank you for recommendations.
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