What Makes a Map Useful?

What makes a good map? Better question – what makes a useful map? Barbara Tversky writes, “The most useful maps distort what they predict and leave out tons of possible information.” It may seem counterintuitive, but we can use this same map-designing logic with our own planning, processes, and most importantly – our communications. 

Tversky uses the London Tube map as an example. She explains how Harry Beck first drew the modern Tube map back in 1931. On paper, it resembles an electronic circuit board – not at all an accurate depiction of how the tracks are laid. Beck’s key insight was that the trains didn’t need his map to know where to go, it was the travelers who needed to know which trains had connections at which stations so they could get from point A to point B. Beck cleanly illustrated the stations and their connections with straight lines and color codes. Stop for a moment and consider how his distortion is what makes the map most useful to its intended audience.

The same logic applies any time we’re proposing a plan to a client or a new system to our colleagues. Everything “behind the scenes” reliably amounts to too much data. Our job is to distill the mountain of engineering, construction, and physical geography down to simply what matters to the end-user. We have to ask, “What does the passenger really want to know? What’s the clearest way to present them with the information?”

The exercise of data reduction is where most of our value is created. Our job is to understand our audience well enough to present them with a useful, usable map. Whether the map is fully self-explanatory or is the source material for a guided tour, the power is in our presentation. We should think carefully about the maps we use and how simple design and curation can go a long way in separating our work from everyone else’s.