Presenting Data on a Map
Below you will find a three different data series for countries across Europe. The legend in the upper right corner states that:
- The orange data point is for the percent of unemployment
- The yellow data point is for the percent change in GDP
- The red data point shows the percent auto sales, which is atrocious
Typically, I find that overlaying data on a map doesn’t really add a lot of value and tends to dilute the message. This chart is one exception that I found. If you had asked me to name these countries without the labels back in the 8th grade, I may have gotten most right. To be honest, I doubt I could name all of the ones on the right (Denmark to Bulgaria) besides maybe Poland, had the labels not been listed.
This chart takes up a lot of room, but I think it’s important to show the relationship (distance) these countries are from each other. Looking at the data, I wonder why Poland has a fairly high unemployment rate with the best auto sales. Then, looking at Poland’s neighbors, it further questions why the numbers are so different. That conclusion would be much harder had the map not been shown.
Yes, you could list these countries out in a bar chart, but showing their proximity to each other adds a great deal of value, in my opinion.
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Most Commented Posts
March 5th, 2009 at 11:06 am
Having the data linked to a map does provide some interesting geographical context. However, it makes comparisons between more than a pair of countries difficult.
Re Poland: maybe their slump started a year earlier, so auto sales had already tanked.
March 5th, 2009 at 11:18 am
@Jon – Two very good points. My first reaction was to present the data is a better format to allow an easier cross-country comparison. However, I think there is no right answer because *it depends* on the goal of the visualization.
I think a bar chart is probably the right answer to compare various countries, but the proximity comparison is much easier with a map. Ideally, the map accompanied by a bar chart would allow for both comparisons. But that would take up a lot more space.
Re: Poland – A drill in to see a multi-year trend would be nice.
Thanks Jon!
March 5th, 2009 at 11:52 am
But are scattered boxes with leader lines the best way to present the data and the map? Perhaps it would have been better as a table, and an adjacent map to be the geographical key?
And why not sort and group the countries in the table? Fourteen countries could be lumped in four groups of three or four (4=roughly the square root of 14), with the lumping designed to prompt the same questions you asked about Poland and its neighbours.
(See my article on sorting and grouping and why I think grouping boosts the power of sorting
It’s an oddly bitty list. Why Spain but not Portugal, France but not the Benelux countries?
April 1st, 2009 at 6:32 am
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