Assume that we asked 20 subjects to participate in a smoking cessation study. We recorded their craving for a cigarette before and after applying a nicotine patch. One reason we might want to use a distribution-free test is because
A) we have too few subjects for a parametric test.
B) there are some outliers that we don't want to have undue influence on the results.
C) the data are normally distributed.
D) the subjects are all male.

Question

Quizplus · Accepted Answer

Distribution-free tests, also known as non-parametric tests, are useful when there are outliers that could unduly influence the results of parametric tests, which assume a normal distribution.

Assume That We Asked 20 Subjects to Participate in a Smoking