### accuracy Go back to the [[AI Glossary]] The fraction of predictions that a classification model got right. In multi-class classification, accuracy is defined as follows: $$Accuracy = \frac{Correct Predictions}{Total Number of Examples} $$ In binary classification, accuracy has the following definition: $$Accuracy = \frac{True Positives + True Negatives}{Total Number of Examples} $$ See true positive and true negative.