0.1 I. j. good: an appreciation

(This module helps introduce The Good Book: Thirty Years of Comments, Conjectures and Conclusions, by I.J. Good . The book is available for purchase from the Rice University Press Store . You can also visit the Rice University Press web site .)

I. j. good—an appreciation

I was privileged to attend a ninetieth birthday celebration in December 2006 for one of the major figures of twentieth-century statistics, and oneof my personal heroes—I.J. Good, known to most of us as Jack. My interactions with Jack, both personal and intellectual, go back overforty years and I am greatly in his debt. It is a pleasure to be able to comment, albeit briefly, on some of his contributions to theliterature that have influenced me the most.

December would have also marked the ninetieth birthday of another major figure and hero of mine, Fred Mosteller, who passed away after anextended illness in July 2006. It was while working on my initial research project under Fred's guidance as a graduate student atHarvard that I first encountered Jack's work. I stumbled across a paperback copy of The Scientist Speculates (Good, 1962), and in it I found a short piece on assessing probability assessors, byBruno de Finetti (1962). At the time I was trying to polish up a memorandum (Tukey, 1965) on the topic initiated bysome notes from John Tukey. Both the memo and the de Finetti piece were to exert a strong influence on my later collaboration with MorrieDeGroot on this topic—after we both had a conversation about it with Jack at the first Valencia meeting in 1979. (It was at Valencia that Ifirst heard Jack describe the role of “fuzzy” priors at the top level of the Bayesian hierarchy!) But as important as that note by deFinetti was, it was in fact the rest of the volume that was so fascinating. And of course most of the entries were written by Jackon almost every topic one could imagine. “Who was this man?” I thought. I was soon to find out.

My next encounter with Jack's work came shortly afterwards. It was his then newly-published book on Estimation of Probabilities (Good, 1965) and his related 1956 article (Good, 1956) on small frequencies in contingency tables.They had a profound influence on my work at the time and reinforced my emerging commitment to the Bayesian perspective. I used ideas fromthis work in my own dissertation research and continued to go back to Jack's “little book” repeatedly in subsequent years, especially as Icame to fully appreciate his explication of the notion of hierarchical models and mixtures of priors, not just for contingency tableproblems. It was also here that I learned about the importance of mixtures of Dirichlet distributions for contingency table problems, atopic Jack returned to repeatedly in subsequent years (e.g., see (Good, 1976) ). My original copy of the book still sits on myoffice shelf, somewhat dog-eared, with many penciled notes and question marks in the margins.

I believe I first met Jack at a professional meeting just after I received my Ph.D. (perhaps in Pittsburgh, although he is likely to rememberbetter than I!), and I believe he spoke on Bode's law (Good, 1969). It was only after going to the University ofChicago where I began to work on log-linear models for multi-dimensional contingency tables that I discovered Jack'sremarkable 1963 Annals paper (Good, 1963) on the use of entropy and marginals to generate log-linear models. Along with keypapers by Birch, Darroch, Goodman, and Plackett, and of course Yvonne Bishop's thesis, that paper served as the foundation of my own work onthe topic. Over the years I have had many occasions to refer others to it, when they “rediscovered” Jack's insights and approach.