A cartographer wants to compare the use in the field (i.e. outdoors) of 6 or 7 different kinds of orthophotomap, not only with each other, but with the conventional (O.S.) style of map. In addition there are 2 types of each orthophotomap, corresponding to 2 different kinds of annotation. There are available copies of all the different kinds of map for an area of approximately 60 square miles in the Berkshire countryside, all maps being on the same scale.
The subjects available, for one day only, are about 20 soldiers all of whom are of average map-reading ability as determined by an earlier indoor map-reading test. The soldiers are to be driven in closed trucks, each holding no more than 4 passengers, to a number of specific sites in the area. It is envisaged that 5 or 6 different sites will be used in order to sample different kinds of landscape (e.g. woody, hilly, urban etc.).
On arrival at a site each soldier will be given one of the kinds of map (either
an orthophotomap or an O.S. map) and a set of map-reading exercises that take
about one hour to complete. Because of difficulties associated with invigilating
soldiers at each site, no two trucks should be at the same site together and
no two soldiers from the same truck should be working on the same kind of map
at the same time.