Figure 5.

(a) Mean $\Delta {\hat{A}}_{\mathit{CV}}$ of each cross-validation method on real data as class fraction varies. (b) $\Delta {\hat{A}}_{\mathit{CV}}$ variances. $\Delta {\hat{A}}_{\mathit{CV}}$: difference between estimated and true AUC; LOO: leave-one-out; LPO: leave-pair-out; TLPO: tournament leave-pair-out; Ridge: ridge regression; KNN: k-nearest neighbors; PCa: prostate cancer.