A sample of back pain sufferers rate their level of pain on a scale from 1 to 7. They then undergo acupuncture treatment. Afterwards, they again rate their level of pain. What is the appropriate test for this study?
A) Wilcoxon matched-pairs signed-ranks test
B) Mann-Whitney test
C) Kruskal-Wallis test
D) Spearman test

Question

Quizplus · Accepted Answer

The appropriate test for this study is the Wilcoxon matched-pairs signed-ranks test, which is a nonparametric test used when comparing the means of two related samples. In this case, the same group of back pain sufferers is being measured before and after the acupuncture treatment. Therefore, the Wilcoxon test is the best choice. The Mann-Whitney test is used to compare the means of two independent groups, the Kruskal-Wallis test is used to compare the means of three or more independent groups, and the Spearman test is used to measure the correlation between two variables.

A Sample of Back Pain Sufferers Rate Their Level of Pain