Fig. 3

Indicative example with high true positive rate (TPR) and high true negative rate (TNR). We show the trend of the four basic rates if TPR = 0.9 and TNR = 0.8, and illustrate how positive predictive value (PPV) and negative predictive value (NPV) depend on prevalence (ϕ). Bookmaker informedness (BM) equals 0.7 in this example. At least one of PPV and NPV is high, even if ϕ varies. Only if ϕ is close to 0.6, both of them are high