Deming's code for statistical practice, published in the premier mathematical statistics journal. The paper articulates principles that transcend specific techniques — the statistician's responsibility for understanding the purpose of a study, the distinction between enumerative and analytic studies, the obligation to understand the subject matter and not merely apply formulas. This paper influenced the development of professional codes of conduct in statistics and reflects Deming's conviction that statistical practice is inseparable from ethics and judgment. Free full PDF from Deming Institute.