In a single sentence the moral is: admit that complexity always increases, first from the model you fit to the data, thence to the model you use to think about and plan about the experiment and its analysis, and thence to the true situation.
John TukeyWhen communicating results to non-technical types there is nothing better than a clear visualization to make your point.
John TukeyAn approximate answer to the right problem is worth a good deal more than an exact answer to an approximate problem.
John Tukey