Prediction of the Void Ratio Parameter in Mineral Tailings Using Gene Expression Programming

Table 4

External validation statistical measures for different approaches.

Item	Performance criteria	Condition	Model 1	Model 3	Model 6	Model 7	Model 8
1	R	R > 0.8	0.967542	0.97819	0.962684	0.983063	0.965097
2	K	0.85 < k < 1.15	1.03594	1.063196	1.044038	1.036733	1.031193
3		0.85 <  < 1.15	0.985769	0.962664	0.98137	0.981004	0.995735
4	Rm	Rm > 0.5	0.713235	0.803656	0.695878	0.805972	0.697069
5	M	|m| < 0.1	−0.06056	−0.02679	−0.06697	−0.02852	−0.06796
6	N	|n| < 0.1	−0.06746	−0.03997	−0.07771	−0.03344	−0.07357