Question

The probability of committing a Type I error is:

Group of answer choices

the level of significance

always less than the probability of a Type II error

1.00 minus the probability of committing a Type II error

equal to the standard error

usually equal to the level of measurement

Answer 1

The correct option is the first option: the level of significance. [ANSWER]

Explanation:

In any hypothesis test, the significance level is defined as the probability of incorrectly rejecting the null hypothesis when in fact it is true. Generally, it is fixed by the experimenter.

Moreover, the Type I error is defined as the event of rejecting the null hypothesis when it is true.

From the last two statements, we observe that the significance level and the probability of committing a Type I error are in fact the same probability and are usually fixed by the experimenter before conducting the hypothesis test.

Thus, the correct option is the first option: level of significance.

Second option: 'always less than the probability of a Type II error' is not correct because the probability of committing a Type I error may or may not be less than the probability of a Type II error.

Third option: '1.00 minus the probability of committing a Type II error' is not correct because '1 - P(Type II error) = Power of the test'.

Fourth option: 'equal to the standard error' is not correct because the probability of Type I error is not equal to the standard error.

Fifth option: 'usually equally to the level of measurement' is not correct because Type I error is not related to the level of measurement.