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PHASES AND SCALES 
1. Classification of phases and scales 
Nearly all those interviewed agreed upon this next division of phases: 
- exploratory 
— reconnaissance 
- semi-detailed 
— detailed 
(project design) 
We can add to this that the exploratory phase is normally not a field survey, 
but a phase that can be done in the office. The data needed for this phase 
can in most cases be derived from literature. In some areas this can even 
apply to the reconnaissance phase. All 16 experts had the consensus of opin- 
ion that the phases mentioned are in a logical sequence, and that in general 
no detailed survey should be undertaken before the prececding rhases have 
been done. The project design rhase as mentioned in the questionnaire was uot 
unanimously seen as a survey phase, but as a logical result of the preceeding 
survey phases, As such it is justifiable to mention it in the list of dif- 
ferent survey phases, 
It emerged that a certain survey phase could clearly be correlated to a cert- 
ain scale. The following scales were considered acceptable: 
- exploratory phase ..... smaller than 1:500.000 
- reconnaissance phase ,.. 1:100.000 - 1:500.000 
— semi-detailed phase ... 1:25,000 - 1:100.0CC 
- deisiled phase ........ larger than 1:20.000 (or 1:25.000) 
- project design ........ larger than 1:10.000 
2. Publication scale - survey scale. 
The publication scale (unanimously defined as the scale on which the map 
is printed or mimeographed for the final report) was considered to be es- 
sentially different from the survey scale. Publication scale is in general 
about a factor 2 smaller than the survey scale. Reduction of the survey sca- 
le is applied because otherwise the map would suggest a higher precision 
than is scientifically justified. For the sociologist and the economist re- 
duction of the survey scale was not a scientific, but a purely cartographic 
and typographic affair (the scale to be reduced as far as possible). 
3. Factors determining phases and scales 
The answers to ihis rather difficult question could be summarized as follows: 
a. It is important that the survey phases should be in a logical sequence, 
e.g. from exploratory to detailed. No detailed surveys should be done 
before the foregoing phase has been carried out or before its equivalent 
is known from literature. This means also that the information (litera- 
ture) already existing of a certain area is an important factor for the 
decision of the survey phase.