Function name

Equation

Reference

Adjusted R²

$R_{adj}^2=1-\left[\left(1-R^2\right)\frac{n-1}{n-p-1}\right]$

[19] [27] [77]

Standard Deviation (SD)

$\text{SD}=\sqrt{\frac{1}{n-1}{\displaystyle \sum }_{i=1}^n{\left(\frac{x_{iexp}-x_{ipred}}{x_{iexp}}\right)}^2}$

[69] [78]

Mean Absolute Error (MAE)

$\text{MAE}=\frac{1}{n}{{\displaystyle \sum }}_{i=1}^n\left|x_{iexp}-x_{ipred}\right|$

[19] [32] [38] [48] [59] [64] [70] [71] [79]

Mean Absolute Relative Error (MARE)

$\text{MARE}=\frac{{{\displaystyle \sum }}_{i=1}^n\left|x_{iexp}-x_{ipred}\right|/n}{x_{emax}-x_{emin}}$

[80]

Average Absolute Relative Deviation (AARD)

$\text{AARD}=\frac{1}{n}{{\displaystyle \sum }}_{i=1}^n\left(\frac{\left|x_{iexp}-x_{ipred}\right|}{x_{iexp}}\right)$

[21] [34] [37] [39] [53] [64] [78]

Absolute Average Deviation (AAD)

$\text{AAD}=\frac{1}{n}{\displaystyle \sum }_{i=1}^N{\left(\frac{x_{iexp}-x_{ipred}}{x_{iexp}}\right)}^2$

[19] [53]