John Tukey

“Numerical quantities focus on expected values, graphical summaries on unexpected values.”

“The greatest value of a picture is when it forces us to notice what we never expected to see.”

“An approximate answer to the right question is worth far more than a precise answer to the wrong one.”

“Far better an approximate answer to the right question, which is often vague, than the exact answer to the wrong question, which can always be made precise.”

“An approximate answer to the right problem is worth a good deal more than an exact answer to an approximate problem.”

“In rating ease of description as very important, we are essentially asserting a belief in quantitative knowledge - a belief that most of the key questions in our world sooner or later demand answers to 'by how much?' rather than merely to 'in which direction?'”