Type I Error Calculator

Calculate Probability of Type I Error

Formula

To calculate the Probability of a Type I Error (\(P(\text{Type I Error})\)):

\[ P(\text{Type I Error}) = \alpha \]

Where:

What is a Type I Error?

A Type I Error, also known as a “false positive,” occurs when a statistical hypothesis test incorrectly rejects a true null hypothesis. This means that the test indicates that there is an effect or a difference when in fact there is none. The significance level (\(\alpha\)) is the probability of making a Type I Error, and it is set by the researcher before conducting the test.

Example Calculation 1

Let's assume the following value:

Using the formula:

\[ P(\text{Type I Error}) = 0.05 \]

The Probability of a Type I Error is 0.05 or 5%.

Example Calculation 2

Let's assume the following value:

Using the formula:

\[ P(\text{Type I Error}) = 0.01 \]

The Probability of a Type I Error is 0.01 or 1%.