In contrast to the clarity and simplicity of the New York Times info graphic mentioned yesterday, the example currently on their home page is an example of the opposite:
This is helpful because it clarifies the point I tried to make about what was nice about the other graphic. Because of space limitations, this graphic is small, and the information is stored across multiple panels. So at the top there are a pair of tabs. Then within the tabs we have a pair of buttons. Two tabs, four buttons, just to get through four possible pieces of data. That’s the sort of combinatoric magic we see in Microsoft Windows preference panels:
While the organization in the info graphic makes conceptual sense—first you must choose one of two states, then choose one of the candidates—it makes little cognitive sense. We’re choosing between one of four options. Just give them to us! For a pair of items beneath another pair of items, there’s no need to establish a sense of hierarchy. If there were a half dozen states, and a half dozen candidates, then that might make sense. Just because the data is technically hierarchic, or arranged in a tree, that doesn’t mean that it’s the best representation for it.
The solution? Just give us the four options. No sliding panels, trap doors, etc. Better yet, superimpose the Clinton and Obama data on a single map as different colors, and have a pair of buttons (not tabs!) that let the viewer quickly swap between Indiana and North Carolina.
(This only covers the interaction model, without getting into the way the data itself is presented, colors chosen, laid out, etc. The lack of population density information in the image makes the maps themselves nearly worthless.)