Table 2.

Statistical performance of QSAR models from 100 times of 51-chemical-hold-out testing (mean and standard deviation) for PKCθ inhibitors.

Paraa	RF		SVM		PLS
	Training	Test	Training	Test	Training	Test
Size	157	51	157	51	157	51
R2	0.95 ± 0.003	0.58 ± 0.09	0.82 ± 0.01	0.49 ± 0.10	0.64 ± 0.13	0.41 ± 0.13
Q2	0.57 ± 0.03	-	0.59 ± 0.02	-	0.39 ± 0.11	-
R2pred	-	0.56 ± 0.09	-	0.45 ± 0.10	-	0.10 ± 0.84
SEE	0.24 ± 0.01	-	0.39 ± 0.01	-	0.53 ± 0.09	-
SEP	-	0.59 ± 0.06	-	0.63 ± 0.05	-	0.79 ± 0.25

^aR², coefficient of determination; Q², cross-validated R²: Q² based on OOB, 10-fold cross-validation and leave-one-out for RF, SVM and PLS, respectively; R²_pred, predictive correlation coefficient for the test set; SEE, standard error of estimate; SEP, standard error of prediction; -, not applicable or available.