While Gian-Carlo was the most important influence on my notes, many other individuals influenced and supported this book. I had the privilege of knowing Mark Kac who, along with Gian-Carlo, taught me the essence of probability theory.

The use of R dates back to when I was visiting the Harvard Medical School. I wish to thank JoAnn Manson, Tianhua Niu, and other members at the Division of Preventive Medicine, Brigham and Women's Hospital and Simin Liu at the Department of Epidemiology, UCLA, for their help and encouragement.

My work on scale-invariant distributions was sponsored by a grant from Amdahl Corporation. I wish to acknowledge the contribution of Dieter Gawlick and Jim Gray in this area.

The material on the Metropolis-Hastings algorithm originated from when I worked with Nick Metropolis, Stan Ulam and Gian-Carlo Rota at Los Alamos.

I also wish to acknowledge the support of Vistology, Inc., especially Mieczyslaw M. Kokar and Christopher J. Matthews, for some of my work on Bayesian networks and influence diagrams.

Special thanks go to my friend, colleague and co-author Tianhua Niu of the Harvard Medical School and the Harvard School of Public Health who generously took time out of his very busy schedule to give a careful and thorough review of my book.

This book would never have been published were it not for Chapman and Hall of the Taylor and Francis Group. I wish to thank Bob Stern, and Dimont, Michele Dimont, Kevin Craig and Marsha Pronin.

Since the book went to press, readers have been sending me suggestions and errata which I greatly appreciate. I wish to acknowledge the help of the aforementioned Tianhua Niu as well as Thomas Chapuis, Ozan Aksoy, Charles Saunders, Danial Viar, John Bottoms, Roger Pinkham, Tom Petersen, Anders Sune Pedersen, and Peter Paprzycki.

Finally, I wish to thank my family for their love, support and encouragement to complete this book.