John Tukey
“An approximate answer to the right problem is worth a good deal more than an exact answer to an approximate problem.” -John Tukey
George Box
“Essentially, all models are wrong, but some are useful.”
Gertrude Cox
“The statistician who supposes that his main contribution to the planning of an experiment will involve statistical theory, finds repeatedly that he makes his most valuable contribution simply by persuading the investigator to explain why he wishes to do the experiment, by persuading him to justify the experimental treatments, and to explain why it is that the experiment, when completed, will assist him in his research.”
R.A. Fisher
"To call in the statistician after the experiment is done may be no more than asking him to perform a postmortem examination: he may be able to say what the experiment died of."