It is difficult to decide how much to alter without destroying the quality that proved so popular. I chose to retain the format and structure of the original book. However, I have removed the chromatic pseudonyms of the investigators.
All new examples utilise real data, the source of which is referenced.
Much has changed in medical statistics since the original edition was published in 1976. Desktop computers now provide statistical facilities unimaginable then, even for mainframe enthusiasts. I think the main change has been an emphasis now on looking and plotting the data first, and on estimation rather than simple hypothesis testing. I have tried to reflect these changes in the new edition. I have found it a useful pedagogic device to pose questions to the students, and so have incorporated questions commonly asked by students or consultees at the end of each chapter.