Because every place worth going can be found on a topo map.
Slate.com recently had an article on how hand-drawn maps are in many ways superior to more ‘accurate’ graphics. Steven Few’s introduction to geographic mapping makes essentially the same point: When there is an abundance of information, including it all merely serves to obscure the important bits. If I need to get the the dry cleaners four blocks away (and I do, at the moment, hooray for job interviews) it doesn’t really help me to know the side streets paralleling my route, or the name of each cross street between my apartment and Jet Cleaners. The best a detailed map can do is confuse me. At worst, I might misread it and end up too far up Dixwell at the wrong time of night.
One of the best maps I’ve ever received was a map of Chicago which consisted of four arrows labeled with street names and a couple of major landmarks that would tell me I’d gone too far. Nothing was to scale, the landmarks were doodles and none of the lines were straight. Still, our car did much better than the other two who were using Google maps, getting there about ten minutes ahead of schedule. Just because you have a lot of data, doesn’t mean you should use it all. Down that road confusion and data minding lie.
Few’s point about color ordering is one that has come up on this blog and in man of the other readings before, so I’ll only mention that color is often less obtrusive and more useful than the sorts of graphics Few recommends. The non-orderabilty (nominal nature) of colors is actually a benefit to a good designer, who can represent both a nominal variable (region) with different colors and an interval variable using intensity at the same time. As Few glosses, in terms of good graphical practice, there is a big difference between mapping regions and mapping locations, even if the map you are using for both is exactly the same.
As for Hurricanes, reading the Steed article without MDX to fool around with reminded me of reading those sex ed. books my parents bought for me in sixth grade. Tantalizing, but without some hands on experience you’re going to miss the point. I can see on principle how a parallel coordinate system with an accessible user interface could be incredibly helpful, but without the chance to play with it I mostly have to take Steed et al. at their word. Looking at the static bundles of lines in the accompanying screenshots, however, was rather unimpressive. But, that’s why so much emphasis was placed on dynamic interactivity!
Chart design consists of as many decisions about what to display as much as it does on how to display it.
