Vignettes for the Year 2000: Theory and Methods Foreword

Abstract

The vignette series concludes with 22 contributions in Theory and Methods. It is, of course, impossible to cover all of theory and methods with so few articles, but we hope that a snapshot of what was, and what may be, is achieved. This is the essence of “vignettes” which, according to the American Heritage Dictionaty, are “literary sketches having the intimate charm and subtlety attributed to vignette portraits.” Through solicitation and announcement, we have collected the Theory and Methods vignettes presented here. The scope is broad, but by no means exhaustive. Exclusion of a topic does not bear on its importance, but rather on the inability to secure a vignette. Many topics were solicited, and a general call was put in Amstut News. Nonetheless, we could not get every topic covered (among other factors, time was very tight). There is some overlap in the vignettes, as the authors, although aware of the other topics, were working independently, and there are places where information in one vignette complements that in another. Rather than edit out some of the overlap, I have tried to signpost these instances with cross-references allowing the reader the luxury of seeing two (or even three) views on a topic. Such diverse accounts can help to enhance our understanding. As I hope you will agree, the resulting collection is nothing short of marvelous. The writers are all experts in their fields, and bring a perception and view that truly highlights each subject area. My goal in this introduction is not to summarize what is contained in the following pages, but rather to entice you to spend some time looking through the vignettes. At the very least, you will find some wonderful stories about the history and development of our subject. (For example, see the vignettes by McCulloch and Meng for different histories of the EM algorithm.) Some of the speculation may even inspire you to try your hand, either in developing the theory or applying the methodology. The question of in which order to present the vignettes was one that I thought hard about. First, I tried to put them in a subject-oriented order, to create some sort of smooth flow throughout. This turned out to be impossible, as the connections between topics is not linear. Moreover, any absolute ordering could carry a connotation of importance of the topics, a judgment that I don’t feel qualified to make. (Indeed, such a judgment may be impossible to make.) So in the end I settled for an alphabetical ordering according to author name. This is not only objective, but also makes the various vignettes a bit easier to find.