Model accuracy level

Small probability of error $p$

Mean square deviation ratio $C$

Level 1 (good)

$\ge 0.95$

$\le 0.35$

Level 2 (qualified)

$0.80\ll p<0.95$

$0.35<C\le 0.50$

Level 3 (barely)

$0.70\ll p<0.80$

$0.50<C\le 0.65$

Level 4 (unqualified)

$<0.70$

$>0.65$