Fast Company’s second article has caused a lot of people to fret over whether this (or Beck’s version) is a map or a diagram. In many ways, this semantic debate is a bit of a distraction. What’s more important than design industry pedantry is what the user will be looking for to help them navigate an unfamiliar city. In most cases when your average man in the street (or on the tube) is looking for something to help them travel from A to B they will be thinking of a map of some sort whether this is the ‘correct’ term or not.
It could also be argued that a map is a very particular type of diagram and the term used by Claire Dobbin in the Independent article, ‘diagrammatic map’ is a suitable compromise. But, as a friend of mine pointed out, you don’t find treasure in a diagram!