“Graphical Excellence” by Edward R. Tufte has many images within his piece. On page 17, he has two maps, but they both have the same issues so focusing in on just one is unnecessary. These maps, which are meant to depict all types of cancer in whites, which are age-adjusted rates by county during the years of 1950-1969, are relatively terrible.
Assuming that whites are the only one who need be depicted – and they’re not, having maps for all of the races instead of just whites would be better, and better yet having many maps depicting different ethnicities instead of broad racial groups would be best for the purposes of research – this map has a number of issues. The map only portrays the continental US. Hawaii and Alaska are completely forgone. The map is made hoping that the layout of the counties will make clear where the state boundaries are. However, the boundaries are hard to see. A thickening of the lines on the boundaries would help with this.
Moving on, this map is broken into counties. This assumes that the observer knows where all of the counties are in each state. However, many of the counties are so small they’re impossible to determine in the first place. Labeling the counties, while messy, would make this far more effective in portraying information. Then there’s the coloration. The key is on a different page altogether, which makes reading this map further impossible to deal with.
Personally, this map fails on aesthetics and information. And I can honestly say the first thing I look for in any infographic is the actual information provided instead of how well it’s laid out. In fact, I may notice the aesthetics only when the layout is so terrible I can’t determine what’s being portrayed.