A map does not just chart, it unlocks and formulates meaning; it forms bridges between here and there, between disparate ideas that we did not know were previously connected.
—Reif Larsen, The Selected Works of T. S. Spivet
In a broad sense of the word, this entire book is about maps, as it deals with the spatial representation of information with the goal of revealing the unseen. In this chapter, I will be using a narrower meaning of “map” to refer just to visualizations that display attributes or variables over pictures of geographical areas.
As any of the other graphic forms we’ve learned about so far, maps can be used to communicate or to explore information. Maps are critical to many areas of inquiry, from epidemiology to ...