tenth. 80—90 % of the areas have been estimated to within 3 
tenths. 
There are no indications of influence of scale on the esti- 
mations. 
9. 25. Estimation of stand age. 
The results of the estimations of stand ages are shown in 
Table 24. 
Approximately 60 9% of the estimated areas have an error not 
exceeding 10 years. Beyond this error the distribution is rather 
considerable. The three interpreters have achieved roughly the 
same results. 
Table 25 shows the number of incorrect estimations (in %) 
nol exceeding 20 and 40 years. 
Table 25 
The number of estimation of stand ages with errors less than 20 and 40 years. 
  
AM 
Interpreter I Il I interpreters 
The error not 
  
  
exceeding 20 | 40 | 20 40 90 | 40 | 20 40 
| | 
Scale 1:16 000 58 1 90 | 78 | 95 loge | 95 74 94 / 
1:926 000 65 (7900 et | 86/84 T 95 72 | 89 
1 : 33 000 "i 876074 82 [85 “95 | 75 | 8 
In more than 70 % the stand ages have been misestimated by 
less than 20 years and in approximately 90 % by less than 40 
years. 
From Table 25 one might possibly conclude a slight tendency 
of a better result for larger scales. 
3. 26. Estimation made on contact prints. 
For the Skedvi field an experiment in estimating stand data 
on contact prints was performed by interpreter III and a forester 
experienced in forestry interpretation (interpreter IV). For the 
estimations, the lens stereoscope mentioned above was used. The 
data were prepared concerning stand mean height and timber 
supply. The results are shown in Tables 26 and 27. 
33