Figure 4A: Areas 'wrongly included' in the category newly 
built-up areas, by one or more interpreters. 
Figure 4B and 4C: Newly built-up areas 'overlooked' by one or 
more interpreters. 
4B: 'Overlooked' by one to five interpreters. 
40: 'Overlooked' by more than five interpreters. 
(reduced, original scale 1:10,000) 
Dh A Ad tn 
a ER A A TT TT UT 
The size of this category differs between interpreters from 0% to 6%, 
with one exception of 11%. (Table 2, column 3). (2) 
Comparison of the two types of error reveals that on the average there 
is twice as much overlooked as incorrectly included: the two errors do 
not cancel each other out ! Except for interpreters 1 and 5, all inter- 
preters are overlooking more areas than they include incorrectly. 
The number of errors is more or less the same for all interpreters. It 
differs from 17 to 24, with an average of 20. The better interpreters 
make only smaller errors. (Table 2, column 4j. 
1. How accurate are the data provided for the city planning? 
Two aspects of the newly built-up area as mapped by an interpreter on 
the topographical base map can be considered: 
  
(2) Interpreter 5 has made a strange error: he coloured areas as newly 
built-up over à clear signature of buildings on the topographical 
map. Such an error is, of tourse, easily detected. 
    
   
SEG 
depu 
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