Assumptions for Statistical Inference

In this article we overview and discuss some of the important practical assumptions underlying statistical inference.What we say, though not new, is stressed insufficiently in teaching statistical methods and applications.We build on the important conceptual difference between enumerative and analytic studies, emphasized by W. Edwards Deming.Our comments, however, go beyond the published views of Deming.We emphasize the assumptions needed for both types of studies and illustrate the concepts with examples.