To Cohn Tukey we can pay the highest tribute possible to a statistician: he has profoundly affected the way we analyze data. The Collected Works demonstrate this. The breadth and impact of his writings are stunning. Whole areas of statistics have their foundations laid and others are inspired � spectrum estimation, multiple comparisons, quick and dirty methods, exploratory data analysis, graphics, robust methods, and Monte Carlo. No area of statistics escapes treatment. The list of applications to science and technology goes on and on; seismology, education, band spectroscopy, halothane, federal statistics, indexing, astrophysics, the Kinsey report, pollution, molecular physics, and halocarbons are a small part of the list. Raw brilliance is everywhere -- the fast Fourier transform, stem-and-leaf diagrams, coining the word "bit", one degree of freedom for no additivity, components of variance, the jackknife, Tukey's Lemma, binomial probability paper, 3RSRH, and so on. The Collected Works are meant to be more than a collection for the record or for future historians to sort out scientific movements. They can be used right now by researchers, by data analysts, and by students. To help readers, The Collected Works have been divided into subjects with an editor for each. The editors have selected just enough papers to convey the philosophies and methodologies of Tukey and have provided comments to guide readers through the writings. Many of John Tukey's writings, including some of his most influential work, have never appeared before in published form. These volumes give the scientific and technological community easy access to this important material.A testimony to the high regard that so many have for Cohn Tukey was the willingness and enthusiasm with which people accepted the invitation to help assemble The Collected Works. Not a single person declined, and the creation of these volumes has been the effort of a team.