A nonparametric method to compare two or more populations, when the samples are independent and the data are either ordinal or interval but not normal, is the:
A) Kruskal-Wallis test
B) Friedman test
C) Wilcoxon rank sum test
D) Wilcoxon signed rank sum test
E) chi-square test

Question

Quizplus · Accepted Answer

The Kruskal-Wallis test is a nonparametric method used to compare two or more populations when the samples are independent and the data are either ordinal or interval but not normal. The Friedman test is also a nonparametric method for comparing two or more populations, but it is appropriate only when the data are paired. The Wilcoxon rank sum test and the Wilcoxon signed rank sum test are nonparametric methods used to compare two populations, but they are appropriate only when the samples are independent and the data are either ordinal or interval but not normal. The chi-square test is used to test the independence of two categorical variables.

A Nonparametric Method to Compare Two or More Populations, When