ABSTRACT
This chapter addresses the ‘What’, which is the topic or theme to be displayed against the background of a (topographical) base map, and the map types applied for this display. Map types are groups of maps that have received their shape according to the similarity in the specific methods used in their design, such as the choropleth method or the isoline method. Most of the topics to be displayed are based on statistical surveys, and this chapter also discusses the processing and analyses of the resulting data. An important aspect of this processing is the data classification. The graphical grammar introduced in Chapter 5 is applied here in order to find the best graphical variables for rendering the data.
Of the various map types not only are their positive aspects discussed, but also their downsides are discussed, such as statistical enumeration areas with irrelevant boundaries, false suggestions of homogeneity, and the inability of most readers to compare circle sizes or to compare diagrams on maps as well as the ways to offset these problems.
