Accuracy level

S/σ

R²

P (%)

Good

<0.4

>0.9

>90

Medium

0.4 - 0.6

0.8 - 0.9

75 - 90

Low level

0.6 - 0.8

0.6 – 0.8

60 - 75

Not achieved

>0.8

<0.6

<60