- “We must keep symbols to a minimum, so as not to overload the reader’s memory. Some ancient authors, by covering their cartograms with hieroglyphics, made them indecipherable.”
- “One of us recommends adopting scales for ordinate and abscissa so the average slope of the phenomenon corresponds to the tangent of the curve at an angle of 45◦”.
- “Areas are often used in graphic representations. However, they have the disadvantage of often misleading the reader even though they were designed according to indisputable geometric principles. Indeed, the eye has a hard time appreciating areas.”
- “We should not, as it is sometimes done, cut the bottom of the diagram under the pretext that it is useless. This arbitrary suppression distorts the chart by making us think that the variations of the function are more important than they really are.”
- “In order to increase the means of expression without straining the reader’s memory, we often build cartograms with two colors. And, indeed, the reader can easily remember this simple formula: ‘The more the shade is red, the more the phenomenon studied surpasses average; the more the shade is blue, the more phenomenon studied is below average.’ ”
These are from a failed attempt to get the International Institute of Statistics to set up some standards for statistical graphics. In 1901.
(from Hadley Wickham)