A non-parametric method to compare two populations, when the samples consist of matched pairs of observations and the data are either ordinal or interval, and where the normality requirement necessary to perform the parametric test is not satisfied, is the:
A) Wilcoxon rank sum test.
B) Chi-squared test.
C) Wilcoxon signed rank sum test.
D) Kruskal-Wallis test.

Question

Quizplus · Accepted Answer

The Wilcoxon signed rank sum test is the appropriate non-parametric method to compare two populations when the samples consist of matched pairs of observations and the normality requirement necessary to perform the parametric test is not satisfied. The Wilcoxon rank sum test is appropriate for independent samples, while the Kruskal-Wallis test is appropriate for comparing more than two independent groups. The chi-squared test is appropriate for comparing categorical variables.

A Non-Parametric Method to Compare Two Populations, When the Samples