The adage "A picture is worth a thousand words" refers to the notion that a complex idea can be conveyed with just a single still image. It also aptly characterizes one of the main goals of visualization, namely making it possible to absorb large amounts of data quickly.
It is believed that the modern use of the phrase stems from an article by Fred R. Barnard in the advertising trade journal Printers' Ink, promoting the use of images in advertisements that appeared on the sides of streetcars.[1] The December 8, 1921 issue carries an ad entitled, "One Look is Worth A Thousand Words."
Another ad by Barnard appears in the March 10, 1927 issue with the phrase "One Picture is Worth Ten Thousand Words," where it is labeled a Chinese proverb (一畫勝千言). The Home Book of Proverbs, Maxims, and Familiar Phrases quotes Barnard as saying he called it "a Chinese proverb, so that people would take it seriously." Soon after, the proverb would become popularly attributed to Confucius.
Despite this modern origin of the popular phrase, the sentiment has been expressed by earlier writers. For example the Russian writer Ivan Turgenev wrote (in Fathers and Sons in 1862), "A picture shows me at a glance what it takes dozens of pages of a book to expound."
The quote is sometimes attributed to Emperor Napoleon Bonaparte, who said "Un bon croquis vaut mieux qu'un long discours," or "A good sketch is better than a long speech". (E.g. an EXIT sign pictogram). While this is sometimes translated today as "A picture is worth a thousand words," this translation may not predate the phrase's common use in English.
Computer programmer and author Fred Brooks makes a similar statement regarding programming in The Mythical Man-Month: "Show me your flowcharts and conceal your tables, and I shall continue to be mystified. Show me your tables, and I won’t usually need your flowcharts; they’ll be obvious." The phrase has also been spoofed by John McCarthy, the famous computer scientist, to make the opposite point: "As the Chinese say, 1001 words is worth more than a picture."[2]