Maps are not neutral -- or, rather, the creation of maps is not a neutral process. The choice of what the map covers, and what details to include or exclude, is an inherently subjective process. We saw an example of that recently in the Chicago Crime Map, in which all offenses looked the same, and the data only covered arrests, not convictions (i.e., whether a crime has actually been committed remains legally in doubt). (Update: the very first comment below is from Chicago Crime Map, telling us that they added a color difference between different crime types shortly after I first took a look at them. Thanks!) Another example comes to us from Future Feeder, one that is extremely well-presented yet invites bigger questions about objectivity and information.
The Iraq War Fatalities map is a Flash-based display of Coalition deaths over the course of the conflict, up to June 27, 2005. The fatalities are shown as small dots on the map reflecting their location, and are listed day-by-day; sound and color are used to represent how many died on a given day (I highly recommend running the map with sound on). It's a simple display, but quite powerful.
The map is arguably very informative, in that it makes it easy to get a sense of the patterns of violence over the course of the war. For example, it lets users see: where the conflict is ongoing, and where it is sporadic; where there are cycles matching the months or seasons; and to what degree the conflict is localized, and to what degree it is spread throughout the country. The Iraq War Fatality map is an impressive presentation of the war's spatial, temporal and level-of-violence characteristics; it's a format that could apply well beyond this particular case. One could imagine using the method for the display of car accidents, customer service calls, or any other set of information where the location and intensity vary over time.
But it's impossible to escape the political aspect of the map. Causes of death are not distinguished, and neither does it include listings of objectives achieved -- a useful piece of data, in particular, for measuring against the rising and falling patterns of violence. Similarly, the number of Iraqi deaths is missing; the makers of the map originally wanted to include them, but found that they could not get reliable numbers. But by not listing Iraqi deaths -- whether civilian, government or guerilla-- the focus becomes entirely on the costs to Coalition forces, particularly the US.
The Iraq War Fatality map is simultaneously a terrific example of how multiple categories of data can be displayed via mapping and how hard it is to present complex sets of information completely.