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Estimating Methods, Variability, and Sampling for Drop-Test Data

Appendix—Details on Cups, Error Variance, and Grid Spacing Continued

Table 13–Second comparison of observed gpc (gallons per 100 square feet) values from a 10- by 10-foot spacing with predicted values from a 30- by 10-foot spacing. MAE is mean absolute error and MSE is mean squared error.
  TRUE Triangulation (gpc)
Mean 1.520 1.534
Standard deviation 0.904 0.787
Minimum 0.037 0.081
1st quartile 0.914 0.980
Median 1.374 1.468
3rd quartile 2.046 2.018
Maximum 8.183 3.956
Correlation   0.867
n 418 418
Summary statistics for error distribution
  Triangulation (gpc)
Mean -0.01385
Standard deviation 0.450
Minimum -1.426
1st quartile -0.218
Median -0.017
3rd quartile 0.137
Maximum 4.259
MAE 0.279
MSE 0.202
n 418

Table 14–Third comparison of observed gpc (gallons per 100 square feet) values from a 10- by 10-foot spacing with predicted values from a 30- by 10-foot spacing. MAE is mean absolute error and MSE is mean squared error.
  TRUE Triangulation (gpc)
Mean 1.531 1.538
Standard deviation 0.881 0.846
Minimum 0.037 0.102
1st quartile 0.916 0.998
Median 1.400 1.387
3rd quartile 2.027 2.060
Maximum 5.081 6.132
Correlation   0.846
n 396 396
Summary statistics for error distribution
  Triangulation (gpc)
Mean -0.00609
Standard deviation 0.480
Minimum -3.092
1st quartile -0.191
Median -0.028
3rd quartile 0.171
Maximum 2.545
MAE 1.531
MSE 0.230
n 396

Image of two graphs showing quantile-quantile plots comparing distributions. The title is "Two comparisons of predicted and observed values, The predicted values come from using a 20- by 10-foot grid to triangulate values to form a 10- by 10-foot grid. Y axis of each graph is the predicted values using 20-foot rows, 10-foot columns, and the x axis is observed values.
Figure 24—Quantile-quantile (QQ) plots comparing distributions.

Image of three graphs showing quantile-quantile plots comparing distributions. The title is "Two comparisons of predicted and observed values, The predicted values come from using a 30- by 10-foot grid to triangulate values to form a 10- by 10-foot grid. Y axis of each graph is the predicted values using 30-foot rows, 10-foot columns, and the x axis is observed values.
Figure 25—Quantile-quantile (QQ) plots comparing distributions.

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