Monday, September 23, 2019

How to build a data narrative

On Friday September 20, the Wall Street Journal published the following infographic by Aaron Zitner, Dante Chinni, Jessica Wang, Lindsay Huth, and Danny Dougherty (the online version is paywalled):

In the past few weeks I've been talking to students about how to structure data and visualizations into narratives to produce infographics like this. Let's use this piece as an example.

We begin with a title or headline that summarizes the main point of the piece or anticipates what you're about to see:

The first section provides big figures and highlights key takeaways to spark interest:

After that, we dig deeper into details. The WSJ infographic contains several vertical dot histograms like the one below. Each dot is a district, and the color corresponds to whether each of them leans Democrat or Republican. The lines on top of the dots display the 2008 distributions; there are stark differences between that year and the present: richer districts have become more Democratic and poorer ones more Republican:

Notice also that last horizontal graph; the authors could have made a simple dot plot or lollipop graph, but decided instead to emphasize the change with arcs. I like it.

Next, we move on to explain the reasons for the polarization: different industries, population density, education, and others:

And then a nice conclusion about why all this matters: because the less people have in common with one another, the harder it is to recognize problems that don't affect us: