i 
0 
hA 
e 
Percentage accuracy 
£e 
e 
60 
80 
100 
100 
80 7 
Percentage error 
60 7 
40 7 
207 
nsi Re RR 
— rid squares 
= = — dot grids 
  
  
  
0 
2ha. 
3 T 
tha. Q.5ha. 025 ha. 
Density of observation 
Figure 2 Relationship between percentage error and density of 
observation: when a given unit is 5% of survey area. 
0 
9 
© 
Percentage accuracy 
EB 
e 
60 
80 
100 
100 7 
80 7 
Percentage error 
60 7 
40 7 
207 
——- grid squares 
= — - dot grids 
> - 
— € 
  
  
3 y 
ha. 05ha. 025 ha. 
Density of observation 
Figure 3 Relationship between pecentage error and density of 
observation: when a given unit is 20% of survey area. 
832