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: