This book provides statisticians and researchers with the statistical tools (equations, formulae and numerical tables) needed to design clinical studies and carry out accurate, reliable, and reproducible analysis of the data obtained. For this second edition, six entirely new topics have been added and many chapters have been considerably expanded. This edition also comes packaged with a free computer disk. The disk contains a software application designed to be used in conjunction with the text, which greatly simplifies the process of looking up tabulated, sample-size values.