Table 3.

External validation parameters of the 2D-QSAR models.

External validation metrics	GFA- MLR Model	GFA-ANN (5-3-1)	Threshold	Comment	Reference
Pearson Correlation squared (${\text{R}}_{\text{test}}^2$)	0.6975	0.7003	R2test > 0.6	Passed	(Tropsha, 2010)
$R_{pred}^2$	0.6034	0.5899	$R_{pred}^2$ >0.5	Passed
Δ ${\overline{R}}_m^2$ (test)	0.0842	-	<0.5	Passed
$r_0^2$	0.6585	-	>0.5	Passed
RMSEP	0.0863	0.0827	-	-
r'20	0.6797	-	>0.5	Passed	(Tropsha, 2010)
(r2-r02)/r2	0.0558	-	(r2-r02)/r2 < 0.1	Passed
K	0.9927	-	0.85 < k < 1.15	Passed
(r2- r'20)/r2	0.0254	-	(r2- r'20)/r2 < 0.1	Passed
k’	1.0069	-	0.85 < k’ < 1.15	Passed
$\left|r_0^2-\text{r}{\text{′}}_0\right|$	0.0211	-	$\left|r_0^2-\text{r}{\text{′}}_0\right|$ <0.3	Passed