Statistical Atlas of the United States, Based Upon the Results of the Eleventh Census (1890) - plate 40: Density of distribution of the natives of the Germanic nations: 1890
The pattern
This still is filed under Data as proof.
Define
A chart, map, or count that is the argument, not an illustration next to the argument.
Mechanism
Sighted evidence. The reader is asked to believe their eyes: a bar, a share, a spread on a map.
Verdict
The claim is comparative or quantitative and the figure can be read without a caption doing the sell.
Why it works
Pairing an absolute map with a rate map on the same sheet, at the same size and in the same ramp, is the cleanest way to make the base-rate problem visible: the reader sees the two answers contradict each other and cannot walk away with the naive one. The ramp is sequential rather than categorical, so darkness reads as more without any legend lookup. Using a cool blue base map under a warm data ramp keeps the geography readable while never competing with the variable. Printing the class breaks as numbers inside the key, plus the footnote excluding country with fewer than two persons to the square mile, forecloses the obvious objection before a critic can raise it.
Steal this when
Use this pairing whenever a count and a rate tell opposite stories, revenue by region versus revenue per customer, and stakeholders keep arguing from whichever one suits them. Put both on one page, same size, same colour ramp, and let the contradiction be the point.