The Empty Square

Think of somewhere you know that is not on the map. A shop that opened last year, a path everyone in your neighbourhood uses. You know it is there and the map says nothing is. Every blank space on every map is one of two things: nothing is there, or nobody has told the map yet, and a map draws those two exactly the same. Four lessons in reading maps, tested against 14,510 humanitarian mapping projects and every UN humanitarian appeal since 2014. Volunteered geographic information and why it exists where volunteers are rather than where it is needed. Why zero and blank are different facts. How to test an idea you want to be true. And what happens when you divide by something that was measuring a different thing.