A smiley-face is very expressive, statistically. By tweaking the eyes, mouth and other bits, you can literally put a meaningful face on any jumble of numbers. Herman Chernoff pointed this out in 1973 in the Journal of the American Statistical Association, in a monograph called The Use of Faces to Represent Points in K-Dimensional Space Graphically.
Subsequently, folks took to calling these things Chernoff faces. Chernoff faces can make statistical analysis into a recognisably human activity. Most people, when shown some statistics, sigh and get boggled. But Chernoff realised that almost everyone is good at reading faces. So he devised recipes to convert any set of statistics into an equivalent bunch of smiley-face drawings….
So begins this week’s Improbable Research column in The Guardian.