nRMSE
nRMSE, or normalized root mean square error, is a scale-free statistic used to assess the accuracy of predictions by dividing RMSE by a normalization term. By normalizing RMSE, it facilitates comparisons across datasets or models with different units or ranges.
Calculation: Given observed values y_i and predicted values ŷ_i for i = 1..n, RMSE = sqrt( (1/n) sum
Interpretation and considerations: Lower nRMSE indicates a better fit. Because the normalization changes the scale, different
Applications: Widely used in environmental modeling, hydrology, meteorology, and machine learning to compare forecast accuracy across