Curves of Constant PPV Robustness.

The sensitivity, σ, and the specificity, ψ. The estimated prevalence, π~, is 0.01, and the estimated error of π~ is w_s=π~/3. The expert estimate of the positive predictive value, PPV, is denoted PPV_e=0.75 PPV. The acceptable error of this estimate is ɛ=0.05. The robustness to uncertainty is denoted ĥ.

π~=0.01, w_s=π~/3, ɛ=0.05, PPV_e=0.75 PPV at each (σ,ψ) point.