You may have heard that “all maps lie” and that’s right (also, here’s some required reading). Each map is a collection of compromises, whether they’re geomatic (your projection and scale choices), editorial (your choice of subject and what you’ve chosen to show and not show), and thematic (how you choose to show quantitative information). There are myriad others of course, too. The gist is maps carry with them the galaxy of choices of their makers, for better or worse. We want to push our maps on the “for better” side of that balance.
Let’s take a look at how our choice of classification method impacts the message communicated to your readers. Here are a handful of the more common classifications, and the profound visual impact they have. This video is a small segment of the Going Places with Spatial Analysis MOOC. Learn more about that free course, here.
0:00 Mind-bending intro
0:24 Why classify?
1:35 Equal Interval
2:30 Standard Deviation
3:09 Quantile
3:47 Natural Breaks
4:20 Just skip to this handy summary
5:29 Confusing ending
All maps are messengers, and the message they carry has a lot to do with our choices. We makers have a wonderful responsibility to do right by the phenomenon we reveal. The first step is understanding our options and making a thoughtful choice—always with the earnest goal of telling the truthiest version of the truth.
Happy mapping! Love, John