The Georgia Negro: A Social Study - Albany, Dougherty County, Ga. Distribution of 2,500 Negro inhabitants
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
One dot per household at the true lot position is the whole method - no district shading, no averaging, so the clustering is produced by the data rather than imposed by the mapmaker's boundaries. Encoding class in colour on top of position lets two variables be read at once: where people live and how they live. Demoting whites to a bracketed line at the bottom of the key inverts the default figure and ground of American maps of the period, and makes Black residence the subject rather than the exception. The empty blocks carry as much argument as the filled ones.
Steal this when
When aggregate numbers are being used to dismiss a problem, plot the raw units at their true positions and let the clustering speak. Works for customer, incident or coverage data where a regional average hides the actual concentration.