Question

In a hypothesis testing problem, the observed level of significance is:

A) the probability of not rejecting the null hypothesis when it is false

B) the confidence level of the associated interval estimation problem

C) one minus the confidence level of the associated interval estimation problem

D) the probability of rejecting the null hypothesis when it is true

E) the probability, calculated under the null hypothesis of obtaining a random sample of the same size containing even stringer evidence against the null hypothesis than is contained in the data sample

Answer 1

In a hypothesis testing problem, the observed level of significance is the probability of rejecting the null hypothesis when it is true.

Explanation:

Level of significance is probability of type 1 error.

Type 1 error is rejecting the null hypothesis when it is true.

And the probability of type 1 error is level of significance.

Therefore level of significance is the probability of rejecting the null hypothesis when it is true.

Note that size of the test does not exceed level of significance. In many cases they are equal.