What Story Does Your Data Visualization Tell?
I had opportunity this week with a client to reference a 19th-Century illustration by Charles Joseph Minard, a Frenchman who depicted the tragic loss of life in Napoleon’s ill-fated march to Moscow (and back) in 1812-1813. I see it as a forebearer in many ways of modern elegant ways to represent information and I was using it to make a point about data visualization.
I think it’s important to see that people have always clamored for the best visual representations and it can be the “other half” of the work in developing analytical systems – the first half being data management. Over the long haul, I suspect data usage and representation constitute a majority of the work, eventually overcoming data management (including sourcing, integration, modeling, quality, etc.).
Back to Minard, I have always found the story of the march and its representation in this graph fascinating.
The march (to Moscow in brown, return in black) is plotted on a lightly exposed map of Europe naming all battles – on the path taken by the army. They started out with a force of 432,000 (on the left). Proceeding eastward, the army, under constant attack, slowly dissolves until on the far right we see only 100,000 made it to Moscow. The width of the line narrows perfectly according to the attrition dealt by the Cossacks.
The 100,000 turned around (Russia had set Moscow ablaze to prevent its plunder) and a more pronounced thinning in the ranks occurs on the way back to France until (far left) only 10,000 make the full journey. Russian tactics had prevented French army access to food sources along the way and forced the retreat on a similar path as the advance. That’s a loss of 39 out of 40 soldiers – devastating. This was a major turning point in the Napoleonic Wars.
Minard plotted the temperature for the retreat, an obvious factor, as well. Dreams of French conquest began to cease (though the chart’s impact on that is debatable.)
It’s a multi-faceted, yet powerful chart. It’s creative and immensely informative. It was obviously done by hand, but I wouldn’t want it to be any different today with modern tools.
A chart like this was worth it then, even with all the effort poured into it. And it is worth it now. With this, and other works, Minard showed us that, if done well, data visualizations can tell important stories.
This post was written as part of the IBM for Midsize Business program, which provides midsize businesses with the tools, expertise and solutions they need to become engines of a smarter planet. I’ve been compensated to contribute to this program, but the opinions expressed in this post are my own and don’t necessarily represent IBM’s positions, strategies or opinions.