Table 1. Statistical Measures of Correlation for the COMBINE Analysis Models Derived for log(k_off) of HSP90 and HIV-1 Protease Inhibitors^a.

	HSP90			HIV-1 protease
validation	Q2	AAEV	RMEV	Q2	AAEV	RMEV
leave-one-out (LOO)	0.69	0.45	0.57	0.70	0.58	0.75
leave-two-out (L2O)	0.69	0.45	0.58	0.51	0.68	0.96
leave-three-out (L3O)	0.68	0.46	0.59	0.52	0.68	0.95
random groups of 7 (10 iterations)	0.68	0.46	0.59	0.60	0.63	0.86

^aCross-validated correlation coefficient (Q²), average absolute errors (AAE_V), and root mean squared errors (RME_V) for different validation methods are given for the PLS models derived with three latent variables for HSP90 inhibitors and six latent variables for HIV-1 protease inhibitors.