Table 36. Model performance evaluation statistical measures used to evaluate CTMs. Statistical Mathematical Notes Measure Expression Accuracy of Comparison paired peak of the peak (Ap) observed value (Opeak) with the predicted value at same time and location Coefficient of Pi = determination prediction at (r2) time and location i; Oi = observation at time and location i; = arithmetic average of Pi, i=1,2,…, N; = arithmetic average of Oi, i=1,2,…,N Normalized Reported as Mean Error % (NME) Root Mean Reported as Square Error concentration (RMSE) (e.g., µg/m3) Fractional Reported as Gross Error % and (FE) bounded by 0% to 200% Mean Error Reported as (ME) concentration (e.g., µg/m3) Mean Reported as Normalized % Gross Error (MNGE) Mean Bias Reported as (MB) concentration (e.g., µg/m3)
Table 36. Model performance evaluation statistical measures used to evaluate CTMs. Statistical Measure Mathematical Expression Notes Accuracy of paired peak (Ap) Comparison of the peak observed value (Opeak) with the predicted value at same time and location Coefficient of determination (r2) Pi = prediction at time and location i; Oi = observation at time and location i; = arithmetic average of Pi, i=1,2,…, N; = arithmetic average of Oi, i=1,2,…,N Normalized Mean Error (NME) Reported as % Root Mean Square Error (RMSE) Reported as concentration (e.g., µg/m3) Fractional Gross Error (FE) Reported as % and bounded by 0% to 200% Mean Error (ME) Reported as concentration (e.g., µg/m3) Mean Normalized Gross Error (MNGE) Reported as % Mean Bias (MB) Reported as concentration (e.g., µg/m3)