AI engineering glossary · Evaluation metrics
What is TNR (specificity)?
Specificity (also called true negative rate, TNR, selectivity): The share of all real negative cases that the model correctly labels negative: TN / (TN + FP). It is the mirror image of recall and equals one minus the false positive rate. It is widely used in medical testing alongside sensitivity.
Specificity: an example
Of 980 genuine transactions, 970 are cleared correctly, so specificity = 970 / 980, about 0.99.
Related terms
More Evaluation metrics terms
- Symmetric mean absolute percentage error
- Temperature scaling
- Token-level F1
- Translation edit rate
- True negative
- True positive
- V-measure
- Weighted averaging
Where you learn it
Specificity is part of the AI Engineering Program, which teaches it with notes, a hands-on lab and an exam. The first lesson is free.