Specificity - Definition and Overview

In binary testing, e.g. a medical diagnostic test for a certain disease, specificity is the proportion of true negatives of all the negative samples tested, that is

<math>{\rm specificity}=\frac{\rm number\ of\ true\ negatives}{{\rm number\ of\ true\ negatives}+{\rm number\ of\ false\ positives}}.<math>

Note that other definitions of specificity are also in use, such as:

<math>{\rm specificity}=\frac{\rm number\ of\ true\ positives}{{\rm number\ of\ true\ positives}+{\rm number\ of\ false\ positives}}.<math>

See

• binary classification
• receiver operating characteristic
• sensitivity (tests)
• statistical significance
• Type I error