If the usual assumptions behind parametric tests are met (at least approximately),
A) distribution-free tests are more powerful than parametric tests.
B) distribution-free tests are somewhat less powerful than parametric tests.
C) the tests are indistinguishable.
D) you shouldn't use a parametric test.

Question

Quizplus · Accepted Answer

When the usual assumptions behind parametric tests are met, parametric tests are generally more powerful than distribution-free (nonparametric) tests. This means they are more likely to detect a true effect when one exists, assuming the assumptions such as normality and homogeneity of variance are met. Distribution-free tests do not rely on these assumptions and are thus less powerful under these conditions but more versatile overall.

If the Usual Assumptions Behind Parametric Tests Are Met (At