Information Designers Should Not Assume Their Readers Are Stupid (Tufte)

Lurking behind chartjunk is contempt both for information and for audience. Chartjunk promoters imagine that numbers and details are boring, dull, and tedious, requiring ornament to enliven. Cosmetic decoration, which frequently distorts the data, will never salvage an underlying lack of content. If the numbers are boring, then you’ve got the wrong numbers. Credibility vanishes in clouds of chartjunk; who would trust a chart that looks like a video game?

Worse is the contempt for our audience, designing as if readers were obtuse and uncaring. In fact, consumers of graphic are often more intelligent about the information at hand than those who fabricate the data decoration. And, no matter what, the operating moral premise of information design should be that our readers are alert and caring; they may be busy, eager to get on with it, but they are not stupid. Clarity and simplicity are completely opposite simple-mindedness. Disrespect for the audience will leak through, damaging communication. What E.B. White said of writing is equally true for information design: “No one can write decently who is distrustful of the reader’s intelligence, or whose attitude is patronizing.”

Edward Tufte
Envisioning Information (1990, pgs. 34-35)