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ANNEXURE 1: QUALITY CONTROL METHODS

Figure 1: Thematic map of total population showing incomplete data

You need to ensure that:

❏ The spatial features, which contain information on the target population cover the entire
study area.

❏ All the spatial features must have the required attributes associated with them, for instance,
the number of beneficiaries in the target population.

❏ The most recent estimates of these variables should be used and they should be provided
at the smallest spatial level possible.
Service points

To check the completeness of service point data you should do the following:

 Compare the spatial datasets for the service points with lists of service points in your
department.
 Facilities that have not been included in the spatial dataset must be added.

 Check whether all the spatial features have been captured. A simple way of doing this is to
select a random sample of 10% of service points to check whether they have been captured
in the spatial layers of information.

 See whether the spatial features have all the required attributes associated with them. Key
attributes that are needed include the unique identifiers, names, and capacity of the service
points to address the needs of beneficiaries.
Road dataset

The completeness of the road dataset can be checked by overlaying the road data on recent
topographical maps, ortho-images, satellite imagery or in Google Earth. By selecting 100
random points in the study area, checks can be done to see if the roads closest to these 100
random points on the base maps, ortho-images, satellite imagery or in Google Earth are in the
road dataset.

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