Lab #3 Map Discussion

Below are three maps showing the AIDS rate among adults (age 15-29) in sub-Saharan African countries. Using the exact same variable (AIDS rate), each map represents the data in a different way. Given the nature of the variable I am mapping, there are clear advantages and disadvantages to the choices I made in presenting data with each respective map.

Map #1 in my opinion lays out the data in the most clear and user-friendly fashion. In this map, I represented each country with a different color which corresponds to the adult rate of AIDS in that country. The legend clearly states the percentage of adults with age each color corresponds to. I find this to be the most straightforward representation of the information at hand.

Map #2 uses graduated dots centered on each sub-Saharan African country to represent the AIDS rate of that country, larger dots corresponding with a higher percentage of adults with AIDS. While this is also a pretty clear and straightforward representation of the information, I think that it may be harder for map users to distinguish between different sizes of a dot with the same color and shape than to distinguish between color. Also in this case, the dot may interfere with the country label, making the map slightly more confusing to read.

Map #3 is the most misleading and convoluted representation of the AIDS rate. First of all, the legend only distinguishes between minimum, mean, and maximum AIDS rates for all the sub-Saharan countries, with countries falling between these values represented by dot densities between those listed in the legend. Aside from the obvious flaw that no actual numbers are given, just relative rate among sub-Saharan African countries, this is also the most misleading map of them all. Since the AIDS rate in each country is represented by dot density, this manifests itself as a series of points in the country. This would imply that the points are specific objects, such as the location of hospitals or AIDS victims, rather than a representation of a percentage. This "dot density" may be a good representation of point-specific data, or for data having to do with the number of people with AIDS in that particular country, but is terribly insufficient for representing a rate.

These maps illustrate how the same information can be presented in many ways, and the relative success of each choice for its intended purpose. For a statistic like population density, the dot density could be a good and straightforward representation of that variable. For a country's GDP, for example, both graduated colors and graduated dots would be good choices. For my particular variable, I think the graduated colors is by far the best option to make the map most readable and aesthetically pleasing.