Type I and Type II Errors
A type I error occurs when the null hypothesis is true and it is rejected.
A type II error occurs when the null hypothesis is false and it is accepted.
| H0 | True | False |
|---|---|---|
| Accepted | Correct decision Probability = 1 - α |
Incorrect decision: TYPE II ERROR |
| Rejected | TYPE I ERROR Probability = α |
Correct decision |
The probability of committing a type I error is equivalent to the significance level, α.
The probability of committing a type II error is generally unknown, but is denoted by β.
