This edition has some differences from the first edition, such as the under grade chapters have been omitted. The total number of the OSPE has been increased. And many new ideas have been applied. In the first edition, there were 276 OSPE questions and answers, but now total questions and answers are 390 and we have added a new chapter (VIDEO station). There are 28 video clips online at emedicine360.com and answers are in the book.