Type I and Type II error

Type I error (alpha): The probability of finding a difference between two groups when there are none. On the other hand, one minus alpha, is the probability of not finding a difference when there are none. This one minus alpha is also known as Confidence Level.

Typer II error (beta): The probability of not finding a difference between two groups when there is a difference. On the other hand, one minus beta, is the probability of finding a difference when there is one. This one minus beta is also known as Power of the study.

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