determine the measurement accuracy of field measured dimmnesions

Question

Hi , I have 2 columns with measurements , one column is the acurate measurement and the second column is the forcasted measurements , how i can statistically determine what is the accuarcy of the forcasted measuremnts  vis  a vis the accurate measuremnts ?

 

ex:

~~Accurate column forcasted column
1.5 0
1.3 1
0.4 0
0.25 0
0.8 0
0.5 1.3
0.5 0
1 0.8
0.9 2
1.3 1.5
1.2 3
1.85 0.5
1 0
0.5 0.5
3.25 0.5
1.1 1
0.95 0.7
0.25 1.7
1.9 0.7
0 1.7
0 1.3

Answer 1

One way perhaps is to take each pair of values and work out the absolute difference. You could work out the mean and standard deviation for the absolute differences of all the data pairs. You could apply a confidence level test to the results, by measuring how many standard deviations from the mean are the majority of the results (95%, 97.5%, 99% for example).

You could use a visual method by plotting the results on the same graph using different colours for the actual and forecast measurements. This may give you some idea whether to expect correlation. Join values with a vertical line to indicate the absolute difference between each pair.

You could combine methods and compare results.