Table 2 Median, 25 interquartile and 75 interquartile AUC performance of SVM rbf classifier in discriminating TD subjects of different sites, for each harmonization approach and each dataset, using 20 PCs

No harmonization

0.99 [0.97; 1.00]

0.99 [0.96; 1.00]

0.98 [0.93; 1.00]

0.99 [0.95; 1.00]

External

0.44 [0.35; 0.50]

0.41 [0.34; 0.48]

0.53 [0.43; 0.54]

0.49 [0.45; 0.53]

4/5 External

0.50 [0.44; 0.58]

0.47 [0.39; 0.54]

0.58 [0.51; 0.60]

0.52 [0.47; 0.57]

Internal

0.67 [0.59; 0.70]

0.63 [0.61; 0.69]

0.68 [0.58; 0.69]

0.66 [0.60; 0.70]