Foreword to the fourth edition 2001 IF I HAD TO LIMIT MY PROFESSIONAL BOOKCASE TO A SINGLE VOLUME. I WOULD choose this dictionary. With many new entries, updates, and other refinements in the fourth edition, the dictionary has grown from the original slim pocket book into a mature and substantial volume. John Last and his collaborators must be congratulated for their extraordinary devotion and productivity over the past 20 years, from which epidemiologists around the world have benefited. The dictionary's authority stems from its international recognition. It is an mmediate source for students and practitioners to verify their understanding of the increasing number of technical words in epidemiologic practice. It clarifies concepts that may not have been understood in class, fills many gaps in anyone's education, and jogs the memory of near-forgotten terms. It has no equal in the field of epidemiology The International Epidemiological Association is proud to have had such a ong-standing association with the dictionary. We all hope this relationship will continue indefinitely in the future, even though John Last, being mortal, will not He has set a high standard for his successors. We are grateful that he has prepared the way so well to ensure that the dictionary remains of contemporary relevance e coming decade Charles du v Florey International Epidemiological Association www.ieaweb.orgIf I had to limit my professional bookcase to a single volume, I would choose this dictionary. With many new entries, updates, and other refi nements in the fourth edition, the dictionary has grown from the original slim pocket book into a mature and substantial volume. John Last and his collaborators must be congratulated for their extraordinary devotion and productivity over the past 20 years, from which epidemiologists around the world have benefi ted. The dictionary’s authority stems from its international recognition. It is an immediate source for students and practitioners to verify their understanding of the increasing number of technical words in epidemiologic practice. It clarifi es concepts that may not have been understood in class, fi lls many gaps in anyone’s education, and jogs the memory of near-forgotten terms. It has no equal in the fi eld of epidemiology. The International Epidemiological Association is proud to have had such a long-standing association with the dictionary. We all hope this relationship will continue indefi nitely in the future, even though John Last, being mortal, will not. He has set a high standard for his successors. We are grateful that he has prepared the way so well to ensure that the dictionary remains of contemporary relevance in the coming decades. Charles du V. Florey President, 1999–2002 International Epidemiological Association www.ieaweb.org Foreword to the Fourth Edition, 2001 vii