Type II Error

Type II error refers to one of two errors that could be made during hypothesis testing. The concept was introduced by J. Newman and E. Pearson in 1928 and formalized in 1933. A Type II error occurs when the null hypothesis (Ho), that there is no effect or association, fails to be rejected when it is actually false. A Type II error is often referred to as a false negative because the hypothesis test led to the erroneous conclusion that no effect or association exists, when in fact an effect or association does exist. In contrast to Type II errors, a Type I error occurs when the null hypothesis is rejected when it is actually true. The features of Type II and Type I errors ...