You can’t easily wrap a sphere with a piece of foil without there being some overlaps and creases. God only knows the good people at Terry’s would love to know that secret.
It’s one of the reasons that people have such a hard time estimating the relative size of countries: When you try to convert the spherical Earth to a flat map, distortion occurs. The world is not how it appears in atlases – it’s subject to topographic stretching and compressing according to which projection was used to convert it. Each is subject to its own flaws; none are perfect. As a rule, if you preserve accuracy of area, you lose accuracy of shape.
The skill in map-making lies in deciding which projection works for which map. Only then can travelers set out with an accurate knowledge of a country’s surface area, and not try to cross Alaska with half a bottle of water and a light coat.
Similarly, choosing how best to present your data is as important as the information itself. Misinterpretation of data isn’t purely on the journalist’s end – it’s exacerbated when the journalist can’t communicate their findings clearly to their audience.
Case in point, Guardian data journalist James Ball had a… strong reaction… when, during one of our seminars at City University I used a 3D pie chart to display some results. His argument that by doing so I’d dramatically misrepresented the size of a particular segment of the pie is demonstrably true, although I think his calling me ‘the worst person in the world’ was a little strong.
Similarly, Klout features a graph that, by default, only shows the last 90 days worth of your social interaction. It then adjusts the y-axis accordingly, so you don’t see below your lowest score during that period. Quite apart from the nonsensical Klout scoring system, which may as well be Go Johnny Go Go Go Go or Guyball for how indecipherable it is, by not starting the Y-axis at zero they’re arguably misrepresenting the true relative change and ultimate score.
More examples of bad graphs can be found here, at the Bad Graphs Tumblr. Some are truly, face-palmingly bad.
It sounds trivial, but poor visualisation of data can potentially have utterly, utterly catastrophic results. It is, after all, a tool for communicating. If your language skills were poor you wouldn’t be allowed to present vital information and the same should be true for data.
The following are some articles offering simple advice on how to present your data clearly and effectively:
If you have any advice on the subject, please comment below!