A review on heterogeneity test: Some permutation procedures

When dealing with categorical data, generally the notion of heterogeneity may be used instead of that of variability. There are many fields where data may be only represented by nominal categorical variables or by ordinal variables, e.g. opinion polls, performance qualitative assessments, psycho aptitude tests and so on. In this paper we provide a review of some nonparametric methods concerning testing for heterogeneity, based on permutation procedures. Examples of real applications in different frameworks are also shown.