On the question of when to use a parametric test and when to use a nonparametric test, your text discussed two issues. (This discussion has not yet resulted in a recommendation.) The two issues were
A) null hypothesis and hypothesis testing
B) scale of measurement and power
C) random assignment and alternative hypotheses
D) independent data and correlated data.

Question

Quizplus · Accepted Answer

Parametric tests are used when the data meets certain assumptions including the scale of measurement (e.g., interval or ratio) and the distribution of the data (normal distribution), which affects the power of the test. Nonparametric tests are used when these assumptions are not met.

On the Question of When to Use a Parametric Test