Conversations with Data: #14
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Did you know that there’s an infinite number of possible map projections of the Earth? While cartographers may struggle to find the most accurate representation, this variety means that there’s no shortage of beautiful and innovative ways to map in journalism.
But just because you can map, doesn’t mean you should. To share best practices, we asked our resident geography and cartography geeks for some of their favourites.
Maps you like
With the above warning in mind, we thought it’d be helpful to start with some words of wisdom from PolicyViz’s Jon Schwabish:
"Maps are a tricky thing. On the one hand, people love maps because they are familiar and they can find them easily themselves. On the other hand, geographic areas may not correspond to the importance of the data values (consider, for example, that Russia is about the size of the United States and Australia combined) and thus may result in certain distortions."
That said, distortions can be a beautiful thing -- as Jon’s favourite map demonstrates. The map, produced by Brandon Martin-Anderson, plots a point for every person in the United States.
Jon likes it because: "The only thing you see only thing you see on the screen is the data--there are no state boundaries or city labels, no rivers, no lakes. The only thing you see is the data. And the only reason you recognise it as the shape of the United States is because people tend to live on the borders and coasts. This isn't to say we should plot all the data all the time (and probably too many of us show too much data too much of the time), but this map does a great job of focusing your attention directly on the data."
For another great way of distorting with purpose, let’s take a step back in time to 1948 in Braunschweig, Germany. This marks the beginning of Bollmann maps, a brand of unique aerial views of cities around the world. John Grimwade, from the VisCom school at Ohio University, explains why they’re his favourite:
"Using a modified axonometric projection that Herman Bollmann developed, they show an informative view with diminished roofs and exaggerated sides to help us with on-the-ground navigation. Streets are widened so we can clearly see them. And, unlike a perspective map, the scale is constant."
Bollman maps aren’t the only type that overcome scaling issues. There’s plenty of other options, like Mustapha Mekhatria’s favourite: the tilemap.
"A tilemap creates an idealised representation of geography by making every geographic area (e.g., country, state, city) uniform in size. Tilemaps allow you to remove the inherent bias in traditional maps, where some areas have more real-estate on the maps than others. Unless the relative size difference between geographical areas is essential, a tilemap helps bring focus on the data that is of most interest," explained Mustapha, from Highsoft.
"The visual narrative can be used by decision makers to make new investments in improving existing health facilities to meet Indian Public Health Standards (IPHS) guidelines. It answers why (IPHS), where (Geo points highlighted) and what (the resources/facilities) questions. The visual narrative not only answers these, but also captures the inaccurate data nuances."
Finally, who said all maps have to be strictly cartographical? We were intrigued by Marco A. Ferra’s favourite map from National Geographic, pictured below. In explaining why he choose it, Marco said:
"It’s different from a conventional map a Mercator projection, for example) because it compares, in a very visual and straightforward way, the air pollution between different countries, continents, and GNI per capita. At the same time, it presents an additional dimension of information that is usually not available in infographics: intervals – in this case, the range between the cleanest and most air-polluted cities within the countries."
Our next conversation
That’s right, Alberto Cairo is stopping by!
Until next time,
Madolyn from the EJC Data team