Dot Density mapping requires a more delicate balance than any other method studied thus far. Using the denseness and grouping of dots as an interpretation system to identify patterns, concentrations, and absences of the mapped theme is extremely delicate. The slightest variation in size of the dot, scale of the coverage, or dot value can change the impression of the map. A cartographer can completely change what idea is attempting to be relayed by simply changing or modifying one of these characteristics of Dot Density maps. Changing or modifying two or more of these aspects can give the cartographer even more manipulative flexibility, this can also result, however, in undesirable outputs that make the information difficult to interpret.

The key to displaying the mapped theme accurately and user friendly is a perfect balance of these three characteristics. The most problematic of these characteristics is size of the dot. Dot size should be manipulated to the point that the map is easy to interpret. If dot size is too large, the result will be uninterpretable conglomerations of dots. This is not desirable because although users could look at one of these conglomerates and interpret a high concentration of the mapped theme, the extent of this concentration in not measurable. On the other hand, if the dot size is not large enough, there will be gaps between the dots even in areas of large concentrations. This makes interpretations difficult because concentrations and other aerial patterns will be more difficult to decipher. The loss of these two interpretative properties is unacceptable because one of Dot Density mapping’s strengths is to display spatial patterns and concentrations of a discrete mapped theme.

Dot Density maps are sensitive to the scale of the map. This is because when scale is changed and dot size and value are kept the same, the balance of the fore mentioned characteristics is altered. Large, non-interpretable conglomerations will occur again, the entire balancing process will have to be performed again from scratch. If the size and value of the dos were kept proportional to scale, that is if the scale was reduced or enlarged and the size of the dot changed proportionally with the scale, balancing problems will still occur. It is possible if not probable that when the map is enlarged or reduced, dot size will be to small to read or so large that the map appears childish and unsophisticated. After spending much time balancing and making compromises and finding the optimal balance of all these characteristics to suit the cartographer’s needs and wants, a change in scale will be problematic. The desired scale should be determined first. All other calculations should be performed using this one scale and this procedure will reduce the cartographers in lab time drastically.

Dot value is the least obvious characteristic needing manipulation for obtaining an optimal coverage, but also gives the cartographer a great amount of flexibility and must always be taken into consideration. When dots are given a value that is lower than it should be, the map would contain more dots than it needs causing conglomerations that are not interpretable. When dots are given a value higher than is necessary, areas that contain relatively small amounts of the mapped phenomena will not be represented at all. If dots are given a value of one thousand and the mapped theme is mobile homes per county, all counties containing less than four hundred and ninety nine will be omitted. This causes a problem. Balancing of dot size dot value and scale of the map are the keys to a good Dot Density map.

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