The test validation summary

Common rates employed in classificatory testing are the true positive rate (TPR), false positive rate (FPR), positive predictive power (PPP), and negative predictive power (NPP). FPR and TPR are estimated from research samples representing populations to be distinguished by classificatory testing. PPP and NPP are used by clinicians to classify test takers into populations. PPP and NPP depend on the base rate (BR) of population members in the clinician's sample. The authors introduce the test validation summary (TVS) as a means to report within a single graph the FPR and TPR and the ranges of PPP and NPP across all potential sample BRs for any chosen cut score. The authors investigate how the TVS has other applications, including the estimation of local BR for the condition of interest and the estimation of standard errors for FPR and TPR when estimated across multiple independent validation studies of the classificatory test.