Andrew points to the following graph by Adam Bonica as Exhibit A for a chart attracting popular attention but breaking Tufte-ish rules galore:
I have a slightly different view about this chart. I don't think it's popular because people find it "pretty" or "eye-catching". I think it's popular because it addresses a topic people have a fascination about -- as Adam describes it, it's the "ideological ranking of occupations".
Andrew has provided a few pointers on his post, which I won't repeat here.
Instead, I'll point out some questions that come to mind when I look at this chart -- without help from the rest of the article Erik Voeten (who used Adam's chart) wrote, or any domain knowledge of this area of study.
- Non-U.S. readers may not understand blue vs. red. (could guess from liberal-conservative label or left-right orientation but why leave it to guessing?)
- Curious about the horizontal scale. It looks like a standard-deviation type scale but the distributions of probability mass are far from normal (not that they need to be normal)
- There are no occupations to the right of "Oil and Gas" and yet most of the red mass sit to its right. Who are those unnamed rightists?
- Similarly, who are to the left of people in the movie business?
- The data is screaming for a Gapminder style treatment! Would love to be able to click on "professors" or "investment banking" to look at the dispersion within each occupation.
- Not sure how to read the overlapped areas... for example, should I read Auto-dealers as the right tail of the blue distribution or the near-mode of the red distribution?
How do you feel about this chart? Are you attracted to the visual or to the topic?
PS. Adam has put up a new version of the chart, reflecting some of Andrew's suggestions.
He also explains that the vertical axis is related to campaign contributions. Note that the bars plotted are 40th and 60th percentiles so the dispersion for some of these occupations are gigantic.