Nonparametric statistics

Nonparametric statistics

When your data does not fit to a normal distribution, nonparametric statistical methods are required. A number of the nonparametric tests use ordinal data rather than numerical, with the data ranked and sorted in order. For example, nonparametric statistics could analyse a Likert scale ranking survey responses: Strongly Agree, Agree, Neither agree nor disagree, Disagree, Strongly Disagree.

 

Nonparametric statistical tests include:

  • Sign tests
  • Wilcoxon signed-rank test
  • Mann-Whitney U test
  • Kruskal-Wallis H test
  • Mood’s Median test
  • Friedman test
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