The Fourth Workshop on Maximum Entropy and Bayesian Methods in Applied Statistics was held in Calgary, Alberta, at the University of Calgary, August 5–8, 1984. The workshop continued a three-year tradition of workshops begun at the University of Wyoming, in Laramie, attended by a small number of researchers who welcomed the opportunity to meet and to exchange ideas and opinions on these topics. From small beginnings, the workshop has continued to grow in spite of any real official organization or basis for funding and there always seems to be great interest in “doing it again next year.”

This volume represents the proceedings of the fourth workshop and includes one additional invited paper which was not presented at the workshop but which we are pleased to include in this volume (Ellis, Gohberg, Lay). The fourth workshop also made a point of scheduling several exceptional tutorial lectures by some of our noted colleagues, Ed Jaynes, John Burg, John Shore, and John Skilling. These tutorial lectures were not all written up for publication and we especially regret that the outstanding lectures by John Burg and John Shore must go unrecorded.

The depth and scope of the papers included in this volume attest, I believe, to the growing awareness of the importance of maximum entropy and Bayesian methods in the pure and applied sciences and perhaps serve to indicate that much remains to be done and many avenues are yet to be explored.