From Data to Insight
Where there are data, there is insight. However, insight needs know how – know how about data sources, know how about analyzing data (with particular tools), about the context of the data and – last but not least – know how about presenting and communicating the insight.
These steps characterize what for some time now is called data journalism. More than 200 years ago we can find a brilliant example of ‘data journalism avant la lettre’ by the person who is thought to have invented statistical charts (or ‘lineal arithmetic’): William Playfair.
In his book ‘Lineal Arithmetic’ published in 1798 he presents several short articles about trade relations and the income produced by this trade. His aim is to describe long time developments not the actual situation in his difficult period of revolution and war. Mercantilism seems to be the context of his argumentation, but his primary interest surely is to demonstrate his innovative visual presentation.
Open Data 1798
Playfair gets his data from the House of Commons’ yearly accounts. Open Data 18th century!
Analyzing and presenting
Playfair’s data research is quite easily done. There aren’t big data to be traveled. Some time series of import and export data are the result. It’s his presentation that marks the point!
Playfair presents his findings in a new form. The visual presentation of data is his invention, and he proudly explains this visual ‘mode of representing‘ in the introduction of his work. That’s scientific and convincing.
And to make his readers familiar with charts, especially bar charts, he gives a fascinating explanation leading from real-world money staples to abstract bars of a painted chart:
‘This method has struck several persons as being fallacious, because geometrical measurement has not any relation to money or to time; yet here it is made to represent both. The most familiar and simple answer to this objection is by giving an example. Suppose the money received by a man in trade were all in guineas, and that every evening he made a single pile of all the guineas received during the day, each pile would represent a day, and its height would be proportioned to the receipts of that day; so that by this plain operation, time, proportion, and amount, would all be physically combined.
Lineal arithmetic then, it may be averred, is nothing more than those piles of guineas represented on paper, and on a small scale, in which an inch (perhaps) represents the thickness of five millions of guineas, as in geography it does the breadth of a river, or any other extent of country.’ (p.7/8)
Charts and textual explanation go hand in hand. Playfair discusses all charts in short texts. For chart 3 (Germany) – see above – it looks like this:
‘ … to aim at facility, in communicating information’ (p.8)
Communicating information is where Playfair excels. And he has studied how to do this and where his target groups are:
‘ …. we think it better to confine this work to mere matter of fact, as much as possible, being’ fully satisfied that in this small volume is contained what every man in this country, who aims at the reputation of a well-informed merchant, ought to be acquainted with; at the same time, that the Statesman will find in it things which he perhaps already knows, but which are here painted to the eye in a more agreeable and distinct manner than is possible to be done by writing or figures. It is on these grounds that this small, but compendious volume, claims the public attention.(p.4)
The title has the message