Data Visualization For The Kings
Some historical examples of data visualization still amaze us today and can teach us a lot.
Let’s look at an old “dashboard” of over 200 years ago by William Playfair, an English statistician. He is credited to be the father of data visualization having used bar charts, line charts and pie charts for the first time to show numerical entities. The work of Playfair is therefore a fundamental piece in the history of charting and graphics. Playfair drew this chart to visualize the economic entities on the different European nations and it was published in his “Statistical Breviary” in 1801.
He had no technological tool at his disposal, but only a ruler and a compass. With these tools alone, he created a table that never ceases to amaze for the clarity and richness of information on a single sheet of paper. Incidentally, this is also the first case in which a pie chart is used to represent numerical information.
Now let’s try to break it down into its essential components. The circles represent the different European nations, and the area of each circle represents the area in square miles of the nation. The biggest on the left is Russia; the green circle represents the extension in Asia and the red circle is the extension in Europe. Russia is followed by Turkish Empire and then all other countries back them. The size of the Empire is splitted among Europe, Africa and Asia, making it the first pie chart to appear in history.
Then there are two vertical axis, one on the left and one on the right. The bar on the left of each bubble represents the population in the country; the bar on the right instead represents the “revenue”, it is not clear if revenue is comparable to taxes collected in each country or what we call GDP today: the segment that unites the two vertical bars gives us therefore the ratio of revenue per capita.
Recently it happened to us to do a course of data visualization to a team of data scientists of a multinational company, and we gave them as an exercise the underlying dataset to the visualization of Playfair (without showing them the Playfair Chart). The result was depressing and interesting at the same time: some students took the data set and placed it in Spotfire, their company dataviz tool and they could not find a synthetic way to visualize the different variables. Unexpectedly one person, who did not have access to the tool, used his imagination and drawing with a pen on a piece of paper managed to devise a really effective way of presenting data!
This should make us meditate: we often do not think about visualizing the data with our brain, but we are guided by the tool we have on our desktop; instead we should refine our analysis and information design skills without delegating too much to automatic tools — which are only a means, not the end.
Visit us: https://thevisualagency.com/
