Statistics Dictionary
To see a definition, select a term from the dropdown text box below. The statistics
dictionary will display the definition, plus links to related web pages.
Select term:
Type II Error
Two types of errors can result from a
decision rule
.
-
Type I error. A Type I error occurs when the researcher
rejects a null hypothesis
when it is true. The probability of committing a Type I error is called the
significance level
, and is often denoted by α.
-
Type II error. A Type II error occurs when the researcher
accepts a null hypothesis that is false. The probability of committing a Type
II error is called Beta, and
is often denoted by β. The probability of not
committing a Type II error is called the
Power
of the test.
