I presented an introductory workshop at the 9th international Symposium on Spatial Accuracy Assessment in Natural Resources and Environmental Sciences, also known as Accuracy2010 . This presentation is second of three. The first was conducted by Dr Steve Stehman, and the third by Dr Giles Foody
Beginners Guide to TikTok for Search - Rachel Pearson - We are Tilt __ Bright...
Fundamentals of accuracy_assessment_session2_czaplewski
1. Session 2
Fundamentals of Accuracy Assessment
Raymond L Czaplewski
United States Forest Service
Rocky Mountain Research Station
Fort Collins, Colorado USA
1
2. Session 2 Topics
• Different sample designs
– Simple Random Sampling (Systematic Sampling)
– Stratified Random Sampling
• Different sample survey estimators
• Different sample sizes, n=30, 60, 150
• How close are estimates to true value?
• Example of a 30×30 = 900 pixel world
2
3. Hypothetical “real world”
True (reference) population
N N N N N ^ N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N N
N N N N N ^ ^ ^ N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N ^
N N N N N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N N N ^
N N N ^ N ^ ^ ^ ^ ^ N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N ^ ^ N
N N N N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N ^ ^
N N N N N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N ^ N N
N N N ^ ^ ^ ^ N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N N
N N N N N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N N N N
N N N ^ N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N N ^ ^
N N N N ^ N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N N
N N N ^ ^ N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^
N N N ^ N ^ ^ N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N
N N N ^ N N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N
N N N N N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^
N N N N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N ^
N N N N ^ N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ Reference class
N N N N ^ N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ 30×30 = 900 pixels ^ ^
Natural
N N N N N N N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^
Urban
Crop
N N N N ^ ^ ^ ^ N N N N ^ ^ ^ ^ ^ ^ ^ N ^ ^
N N N N ^ N ^ ^ N N N N N N ^ ^ ^ ^ N ^ ^ ^ ^ ^
N N N N N N ^ ^ ^ N N N N N N ^ ^ ^ N ^ ^ ^ ^ N
N N N N ^ N N ^ N N N N N N N N ^ ^ N N ^ ^ N ^
N ^
N N N N N ^ ^ N N N N N N N N N ^ N N N N ^ ^ N N
N N N N ^ ^ N ^ ^ N N N N N N N ^ N N N N N ^ ^ N ^ ^
N N N N ^ N ^ ^ N N N N N N N N N N N N N N ^ ^ ^ N ^ ^
N N N N N N ^ ^ N N N N N N N N N N N N N N ^ ^ ^ ^ ^ N ^ ^
N N N N ^ N ^ ^ ^ N N N N N N N N N N N N N ^ ^ ^ N N N ^ N
N N N N N N ^ N ^ N N N N N N N N N N N N N ^ ^ ^ N ^ N ^ ^
N N N N N N N ^ N N N N N N N N N N N N N N ^ ^ ^ ^ N ^ N N
N N N N N N ^ ^ ^ N N N N N N N N N N N N N ^ ^ ^ N ^ ^ ^ ^ 3
4. Hypothetical remotely sensed thematic map model for this “real world”
Map #1
N N N ^ N ^ N ^ ^ ^ ^
N ^ ^ ^ N ^ ^ ^ ^ ^ ^ ^ ^ N
N ^ N N ^ N ^ N ^ ^ N ^
^ N N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^
N N ^ N N N ^ ^ N ^ ^ ^ ^
^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N ^ N ^ N ^
^ N ^ N ^ N ^ ^ ^ ^ N ^
^ ^ N ^ ^ N ^ N N ^ N ^ ^ N
N N ^ N ^ ^ ^ ^ N N ^ N ^ ^ ^ ^ ^ ^ ^ N N N ^ N ^
N N N ^ N ^ ^ ^ N ^ ^ ^ ^ ^ ^ ^ N ^ ^ ^ N N N ^
N N N ^ ^ ^ ^ N ^ ^ N N ^ N ^ ^ ^ N ^ ^ ^ ^ ^ N N
N N N ^ ^ N N ^ ^ ^ N ^ ^ ^ ^ N N N ^ ^ ^
N N ^ ^ N ^ N N ^ ^ ^ ^ ^ ^ N ^ ^ N ^ N
N
N N ^ N ^ ^ ^ ^ N ^ ^ N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N
N
N N ^ ^ ^ N N N ^ ^ N ^ ^ ^ ^ ^ ^ ^ ^ ^ N
N
N N ^ ^ ^ ^ N N N ^ N ^ ^ ^ ^ N ^ ^ N ^
^
N ^ ^ N ^ ^ ^ N ^ ^ ^ ^ ^ ^ ^ N
^ N N N N ^ ^ ^ ^ ^ ^ N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N ^
N N ^ N ^ ^ ^ ^ ^ ^ ^ ^ ^ N ^ ^ N ^ ^ ^ N ^ N ^
N ^ N N ^ ^ ^ N ^ ^ ^ ^ ^ N ^ ^ ^ ^ N N ^
N N N ^ N ^ ^ ^ N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ 30×30 = 900 pixels
N ^ ^ ^
^ ^ N N ^ N ^ ^ ^ ^ N ^ ^ ^ ^ ^ ^ N ^ N ^
N N N N ^ ^ ^ ^ ^ N N N N N ^ ^ ^ ^ ^ N ^ N ^ N ^ ^
N N N N ^ ^ ^ ^ N N N ^ N N ^ ^ ^ N N N ^ ^ ^ ^ ^ N ^
Map class
N N N N N N ^ ^ N ^ N ^ N N ^ N ^ N ^ N ^ N ^ N ^ N
N ^ N ^ N N N N N N N ^ ^ N N ^ N ^ ^ ^ N N N ^
Natural N
N N N ^ ^ ^ ^ N N N N N N N ^ N ^ ^ N ^ ^ ^ Urban
^ N ^ ^ N ^ ^ ^ ^ N N N ^ ^ N N ^ N N N N N ^ ^ ^ N ^ ^
N ^ N ^ ^ N ^ N N N N N ^ N ^ ^ N N N N N ^ ^ ^ ^ ^ N ^ ^
Crop ^
^ ^ N N N N ^ N ^ N N N ^ N N N N N N N N N N ^ ^ ^ ^ N ^ N
N ^ N ^ N N ^ N N N N N ^ N N ^ N ^ ^ N N ^ ^ N N N
^ N ^ N N N N N N N N N ^ N N ^ ^ N ^ N N ^ ^ ^
^ N N N N N ^ ^ N N N N N ^ N N N N N N N ^ N N ^ N N ^
N N N N ^ N ^ N ^ N N N N ^ N N N N ^ ^ ^ ^ ^ ^ N N ^ N ^ 4
5. Remotely sensed thematic Map #1 True Error Matrix
Error matrix presented by Steve Stehman Reference class
Natural Urban Crop Total
Traditional Analysis: Error Natural 226 27 74 327
Map class
(Confusion) Matrix Urban 18 108 36 162
Reference Land Cover
Crop 89 36 286 411
Mapped Natural Urban Crop Total
Total 333 171 396 900
Natural 0.25 0.03 0.08 0.36 Overall accuracy 69% kappa 51%
Urban 0.02 0.12 0.04 0.18 Reference class
Crop 0.10 0.04 0.32 0.46 Natural Urban Crop Total
Natural 25% 3% 8% 36%
Map class
Total 0.37 0.19 0.44
Urban 2% 12% 4% 18%
Crop 10% 4% 32% 46%
Total 37% 19% 44% 100%
True (reference) population Map #1
N N N N N ^ N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N N N N N ^ N ^ N ^ ^ ^ ^
N ^ ^ ^ N ^
^ ^ ^ ^ ^ ^ ^ N
N N N N N ^ ^ ^ N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N ^ N ^ N N ^ N ^ N ^ ^ N ^
^ N N ^ ^ ^ ^ ^
^ ^ ^ ^ ^ ^ ^
N N N N N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N N N ^ N N ^ N N N ^ ^ N ^ ^ ^ ^
^ ^ ^ ^ ^ ^ ^ ^
^ ^ N ^ N ^ N ^
30×30 = 900 pixels
N N N ^ N ^ ^ ^ ^ ^ N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N ^ ^ N ^ N ^ N ^ N ^ ^ ^ ^ N ^
^ ^ N ^ ^ N ^ N N ^ N ^ ^ N
N N N N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N ^ ^ N N ^ N ^ ^ ^ ^ N N ^ N ^ ^ ^ ^ ^
^ ^ N N N ^ N ^
N N N N N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N ^ N N N N N ^ N ^ ^ ^ N ^ ^ ^ ^ ^ ^ ^ N
^ ^ ^ N N N ^
N N N ^ ^ ^ ^ N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N N N N N ^ ^ ^ ^ N ^ ^ N N ^ N ^ ^ ^
N ^ ^ ^ ^ ^ N N
N N N N N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N N N N N N N ^ ^ N N ^ ^ ^ N ^ ^ ^
^ N N N ^ ^ ^
N N N ^ N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N N ^ ^ N N ^ ^ N ^ N N ^ ^ ^ ^ ^ ^ N ^ ^ N ^ N
N
N N N N ^ N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N N N N ^ N ^ ^ ^ ^ N ^ ^ N ^ ^ ^ ^ ^
^ ^ ^ ^ ^ N
N
N N N ^ ^ N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N N ^ ^ ^ N N N ^ ^ N ^ ^ ^
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N N N ^ N ^ ^ N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N N N ^ ^ ^ ^ N N N ^ N ^ ^ ^ ^
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N N N ^ N N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N N ^ ^ N ^ ^ ^ N ^ ^ ^ ^ ^ ^
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N N N N N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N N N N ^ ^ ^ ^ ^ ^ N ^ ^ ^ ^ ^ ^ ^ ^
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N N N N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N ^ N N ^ N ^ ^ ^ ^ ^ ^ ^ ^ ^ N ^ ^ N ^ ^
^ N ^ N ^
N N N N ^ N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N ^ N N ^ ^ ^ N ^ ^ ^ ^ ^ N ^ ^ ^ ^ N N ^
N N N N ^ N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N N N ^ N ^ ^ ^ N ^ ^ ^ ^ ^ ^ ^ ^ ^
^ N ^ ^ ^
N N N N N N N ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ N N ^ N ^ ^ ^ ^ N ^ ^ ^ ^ ^ ^ N ^ N ^
N N N N ^ ^ ^ ^ N N N N ^ ^ ^ ^ ^ ^ ^ N ^ ^ N N N N ^ ^ ^ ^ ^ N N N N N ^ ^ ^ ^ ^ N ^ N ^ N ^ ^
N N N N ^ N ^ ^ N N N N N N ^ ^ ^ ^ N ^ ^ ^ ^ ^ N N N N ^ ^ ^ ^ N N N ^ N N ^ ^ ^ N N N ^ ^ ^ ^ ^ N ^
N N N N N N ^ ^ ^ N N N N N N ^ ^ ^ N ^ ^ ^ ^ N N N N N N N ^ ^ N ^ N ^ N N ^ N ^ N ^ N ^ N ^ N ^ N
N N N N ^ N N ^ N N N N N N N N ^ ^ N N ^ ^ N ^ N ^ N ^ N N N N N N N ^ ^ N N ^ N ^ ^ ^ N N N ^
N N N N N ^ ^ N N N N N N N N N ^ N N N N ^ ^ N N N N N ^ ^ ^ ^ N N N N N N N ^ N ^ ^ N ^ ^ ^
N N N N ^ ^ N ^ ^ N N N N N N N ^ N N N N N ^ ^ N ^ ^ ^ N ^ ^ N ^ ^ ^ ^ N N N ^ ^ N N ^ N N N N N ^ ^ ^ N ^ ^
N N N N ^ N ^ ^ N N N N N N N N N N N N N N ^ ^ ^ N ^ ^ N ^ N ^ ^ N ^ N N N N N ^ N ^ ^ N N N N N ^ ^ ^ ^ ^ N ^ ^
N N N N N N ^ ^ N N N N N N N N N N N N N N ^ ^ ^ ^ ^ N ^ ^ ^ ^ N N N N ^ N ^ N N N ^ N N N N N N N N N N ^ ^ ^ ^ N ^ N
N N N N ^ N ^ ^ ^ N N N N N N N N N N N N N ^ ^ ^ N N N ^ N N ^ N ^ N N ^ N N N N N ^ N N ^ N ^ ^ N N ^ ^ N N N
N N N N N N ^ N ^ N N N N N N N N N N N N N ^ ^ ^ N ^ N ^ ^ ^ N ^ N N N N N N N N N ^ N N ^ ^ N ^ N N ^ ^ ^
N
N
N
N
N
N
N
N
N
N
N
N
N
^
^ N
^ ^
N N N N N N N N N
N N N N N N N N N
N
N
N
N
N
N
N
N
^
^
^
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^
^
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N
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N N
^ ^
^
N
N N
N N
N N N ^
N ^ N ^
^ N N
N ^
N N N
N N N
^
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N N N N
N N N N
N
^
N N ^ N N
^ ^ ^ ^ ^ N
^ N N ^
N ^ N ^
5
6. True error matrix parameters
Reference class Reference class
Natural Urban Crop Total Natural Urban Crop Total
Natural 226 27 74 327 Natural 25% 3% 8% 36%
Map class
Map class
Urban 18 108 36 162 Urban 2% 12% 4% 18%
Crop 89 36 286 411 Crop 10% 4% 32% 46%
Total 333 171 396 900 Total 37% 19% 44% 100%
Overall accuracy 69% kappa 51%
6
7. True error matrix parameters, graphical presentation
True Map Land Cover area
Natural
37% 19% 44% Urban
True Reference Land Cover area
Crop
0% 50% 100%
Reference class Reference class
Natural Urban Crop Total Natural Urban Crop Total
Natural 226 27 74 327 Natural 25% 3% 8% 36%
Map class
Map class
Urban 18 108 36 162 Urban 2% 12% 4% 18%
Crop 89 36 286 411 Crop 10% 4% 32% 46%
Total 333 171 396 900 Total 37% 19% 44% 100%
Overall accuracy 69% kappa 51%
7
8. True error matrix parameters, graphical presentation
36% 18% 46%
True Map Land Cover area
Natural
Urban
True Reference Land Cover area
Crop
0% 50% 100%
Reference class Reference class
Natural Urban Crop Total Natural Urban Crop Total
Natural 226 27 74 327 Natural 25% 3% 8% 36%
Map class
Map class
Urban 18 108 36 162 Urban 2% 12% 4% 18%
Crop 89 36 286 411 Crop 10% 4% 32% 46%
Total 333 171 396 900 Total 37% 19% 44% 100%
Overall accuracy 69% kappa 51%
8
12. In the real world, we do not know the true classification for all 900 pixels
?
True (reference) population True error matrix
?
900
Reference class
Natural
Urban
Crop
Map class
Natural N ^
Urban
Crop ^
12
13. In the real world, we do know the true classification for 30 sampled pixels
?
Sample of (reference) population
True true (reference) population True error matrix
900
Reference class
Natural
Urban
Crop
Map class
Natural N ^
Urban
Crop ^
13
14. In the real world, we do know the true classification for 30 sampled pixels
?
Sample of true (reference) population True error matrix
900
Error matrix estimate from sample
Reference class
Natural Urban Crop Total
Natural 8 0 2 10
Map class
Urban 0 4 2 6
Crop 2 2 10 14
Total 10 6 14 30
Overall accuracy 73% kappa 58%
Reference class
Natural Urban Crop Total
Map class Natural 27% 0% 7% 33%
Urban 0% 13% 7% 20%
Crop 7% 7% 33% 47%
Total 33% 20% 47% 100% 14
15. In the real world, we do not know the true classification for all 900 pixels
• Let us leave the real world for the next 30
minutes to compare
– Known estimate of an error matrix with a sample
of 30 pixels
– Unknown true error matrix for all 900 pixels
15
16. Comparison of true (unknown) error matrix with (known) sample estimate
True (unknown) error matrix Error matrix estimate from sample
Reference class Reference class
Natural Urban Crop Total Natural Urban Crop Total
Natural 226 27 74 327 Natural 8 0 2 10
Map class
Map class
Urban 18 108 36 162 Urban 0 4 2 6
Crop 89 36 286 411 Crop 2 2 10 14
Total 333 171 396 900 Total 10 6 14 30
Overall accuracy 69% kappa 51% Overall accuracy 73% kappa 58%
16
17. Examples of random sampling error, simple random sample #1, sample size n=30
Area of each Land Cover Type
Sample Map Land Cover area
True Map Land Cover area Natural
Sample Reference Land Cover area Urban
True Reference Land Cover area Crop
0% 50% 100%
User's Accuracy Producer's Accuracy
Crop Crop
Urban Urban
Natural Natural
0% 50% 100% 0% 50% 100%
kappa
Sample
Overall accuracy
True
0% 50% 100%
17
18. Examples of random sampling error, simple random sample #2, sample size n=30
Area of each Land Cover Type
Sample Map Land Cover area
True Map Land Cover area Natural
Sample Reference Land Cover area Urban
True Reference Land Cover area Crop
0% 50% 100%
User's Accuracy Producer's Accuracy
Crop Crop
Urban Urban
Natural Natural
0% 50% 100% 0% 50% 100%
kappa
Sample
Overall accuracy
True
0% 50% 100%
18
19. Examples of random sampling error, simple random sample #3, sample size n=30
Area of each Land Cover Type
Sample Map Land Cover area
True Map Land Cover area Natural
Sample Reference Land Cover area Urban
True Reference Land Cover area Crop
0% 50% 100%
User's Accuracy Producer's Accuracy
Crop Crop
Urban Urban
Natural Natural
0% 50% 100% 0% 50% 100%
kappa
Sample
Overall accuracy
True
0% 50% 100%
19
20. Examples of random sampling error, simple random sample #4, sample size n=30
Area of each Land Cover Type
Sample Map Land Cover area
True Map Land Cover area Natural
Sample Reference Land Cover area Urban
True Reference Land Cover area Crop
0% 50% 100%
User's Accuracy Producer's Accuracy
Crop Crop
Urban Urban
Natural Natural
0% 50% 100% 0% 50% 100%
kappa
Sample
Overall accuracy
True
0% 50% 100%
20
21. Examples of random sampling error, simple random sample #5, sample size n=30
Area of each Land Cover Type
Sample Map Land Cover area
True Map Land Cover area Natural
Sample Reference Land Cover area Urban
True Reference Land Cover area Crop
0% 50% 100%
User's Accuracy Producer's Accuracy
Crop Crop
Urban Urban
Natural Natural
0% 50% 100% 0% 50% 100%
kappa
Sample
Overall accuracy
True
0% 50% 100%
21
22. But how good is the sample estimate? Example, Producer’s Accuracy Urban
Area of each Land Cover Type
Sample Map Land Cover area
True Map Land Cover area Natural
Sample Reference Land Cover area Urban
True Reference Land Cover area Crop
0% 50% 100%
User's Accuracy Producer's Accuracy
Crop Crop
Urban Urban
Natural Natural
0% 50% 100% 0% 50% 100%
kappa
Sample
Overall accuracy
True
0% 50% 100%
22
23. Example: Producers accuracy for urban
Area of each Land Cover Type
Sample Map Land Cover area
True Map Land Cover area Natural
Sample Reference Land Cover area Urban
True Reference Land Cover area Crop
0% 50% 100%
User's Accuracy Producer's Accuracy
Crop Crop
Urban Urban
Natural Natural
0% 50% 100% 0% 50% 100%
kappa
Sample
Overall accuracy
True
0% 50% 100%
Estimated Producer's Accuracy = 80%
Crop
Urban
`
Natural
0% 50% 100%
23
75. In the real world, we do not know the true value
300
Number of samples
200
100
0
0 20 40 60 80 100
True accuracy = 63% % Producers Accuracy
Estimated Producer's Accuracy = 78%
Crop
Urban
`
Natural
0% 50% 100%
75
76. In the real world, we do not know the true value, and we have only 1 sample
Number of samples
10
5
0
0 20 40 60 80 100
% Producers Accuracy
Estimated Producer's Accuracy = 78%
Crop
Urban
`
Natural
0% 50% 100%
76
77. Examples of random sampling error, simple random sample
• Any single sample estimate can differ from
true error matrix from random sampling error
• Given our only sample with n=60, the
estimated urban producers accuracy = 78%
even though the true value is 63%
• However, the sample estimate is expected to
equal the true value over all possible samples
77
78. Examples of random sampling error, simple random sample
• How can we improve reliability of estimate?
• What if sample size increased from n=60 to
n=150?
78
79. Examples of random sampling error, simple random sample #51, sample size n=150
Area of each Land Cover Type
Sample Map Land Cover area
True Map Land Cover area Natural
Sample Reference Land Cover area Urban
True Reference Land Cover area Crop
0% 50% 100%
User's Accuracy Producer's Accuracy
Crop Crop
Urban Urban
Natural Natural
0% 50% 100% 0% 50% 100%
kappa
Sample
Overall accuracy
True
0% 50% 100%
79
80. Examples of random sampling error, simple random sample #52, sample size n=150
Area of each Land Cover Type
Sample Map Land Cover area
True Map Land Cover area Natural
Sample Reference Land Cover area Urban
True Reference Land Cover area Crop
0% 50% 100%
User's Accuracy Producer's Accuracy
Crop Crop
Urban Urban
Natural Natural
0% 50% 100% 0% 50% 100%
kappa
Sample
Overall accuracy
True
0% 50% 100%
80
81. Examples of random sampling error, simple random sample #53, sample size n=150
Area of each Land Cover Type
Sample Map Land Cover area
True Map Land Cover area Natural
Sample Reference Land Cover area Urban
True Reference Land Cover area Crop
0% 50% 100%
User's Accuracy Producer's Accuracy
Crop Crop
Urban Urban
Natural Natural
0% 50% 100% 0% 50% 100%
kappa
Sample
Overall accuracy
True
0% 50% 100%
81
82. Examples of random sampling error, simple random sample #54, sample size n=150
Area of each Land Cover Type
Sample Map Land Cover area
True Map Land Cover area Natural
Sample Reference Land Cover area Urban
True Reference Land Cover area Crop
0% 50% 100%
User's Accuracy Producer's Accuracy
Crop Crop
Urban Urban
Natural Natural
0% 50% 100% 0% 50% 100%
kappa
Sample
Overall accuracy
True
0% 50% 100%
82