341 
- the contour sheet will have, additionally, 3 classes of 'degree of 
difficulty', irregular, average and smooth, giving 15 (5 x 3) 
categories defining contour density and roughness of the terrain, 
it is proposed to prepare feature density classification sheets for 
6 scales of mapping - 1:1000, 1:2500, 1:5 000, 1:10 000, 1:25 000 
and 1:50 000. 
There will be 2 sheets, each containing 3 planimetric features, for 
each scale of mapping. The final document will have 12 (6x2) 
planimetric sheets and 1 contour sheet on the assumption that the 
contour sheet will be independent of scale. 
the final sheets will be compiled from colour separated repromat, 
finished to a fair drawn standard and litho printed. 
Figure 1 illustrates the lay out of the planimetric feature density 
classification sheets. 
Figure 2 is part of the 1:25 000 pilot sheet at a slightly reduced 
scale and shows elements of buildings, water features and 
communications in the medium, medium dense and dense ranges. 
The map information will be abstracted where possible directly from 
colour separated repromat provided by the WG. For example, all the 
water features are generally directly available from the blue plate on 
the small scale sheets. However, where several elements are combined, 
say on one black plate, it will be necessary to digitize all the 
elements of the feature required and redraw these, using an automatic 
drafting table, so that the feature may be separately presented on the 
classification sheet. 
It has been concluded that for the purpose of visual estimation, the 
feature density classification system will have to be presented 
graphically at different scales. However, better modelling will be 
possible at the statistical processing stage of the OEEPE cost 
modelling research task if the various samples are quantified. 
Furthermore when using the system for estimating it will be possible to 
interpolate and extrapolate between the given standards more easily if 
both graphical and quantified data is available. 
CONCLUSIONS 
Creating a feature density classification system and establshing 
standards are necessary stages in the OEEPE cost modelling research 
task. 
By using the standards which will be established, it is felt that 
individual organizations could improve their own estimating 
performance. 
If the established standards are used in investigations into the cost 
performance of new procedures, the resulting publications and reports 
should be more useful to readers. The standards could also be useful in 
scientific publications. 
The standards would be available for use in contract specifications, to 
describe more precisely the nature of the terrain to be mapped. 
Creating the feature density classification system and establishing 
standards will involve some effort and expense which is being borne by 
the OEEPE WG and by the ITC. We trust that worthwhile benefits will 
accrue to the international photogrammetric community and to individual 
contributing organizations.