12.5 Vocabulary terms

Also other names for the same term, and formulas.

• True positive (\(n_{11}\))

• True negative (\(n_{22}\))

• False positive, Type I error (\(n_{12}\))

• False negative, Type II error (\(n_{21}\))

• True positive rate (TPR), Recall, Sensitivity, probability of detection, power. P(predicted positive | total positive) \(\frac{\# True Positive}{\#Condition Positive}\)

• True negative rate (TNR), Specificity, selectivity. P(predicted negative | total negative) \(\frac{\# True Negative}{\# Condition Negative}\)

• False positive rate (FPR), fall-out, probability of false alarm. \(\frac{\# False Positive}{\# Condition Negative}\)

• False negative rate (FNR), miss rate. \(\frac{\# False Negative}{\# Condition Positive}\)

• Prevalence. \(\frac{\# Condition Positive}{\# Total Population}\)

• Accuracy. \(\frac{\# True Positive + \# True Negative}{\# Total Population}\)

• Balanced Accuracy: \([(n_{11}/n_{.1}) + (n_{22}/n_{.2})]/2\) - Adjusts for class size imbalances

• Positive Predictive Value (PPV), Precision. P(true positive | predicted positive) \(\frac{\# True Positive}{\# Predicted Condition Positive}\)

• False discovery rate (FDR). \(\frac{\# False Positive}{\# Predicted Condition Positive}\)

• False omission rate (FOR). \(\frac{\# False Negative}{\# Predicted Condition Negative}\)

• Negative predictive value (NPV). \(\frac{\# True Negative}{\# Predicted Condition Negative}\)

• F1 score. The harmonic mean of precision and recall. This ranges from 0 (bad) to 1 (good): \(\frac{2 * (Precision * Recall)}{Precision + Recall}\)