The present book was an attempt to find the reasons why interpreting trainees coming from similar backgrounds may experience varying degrees of success, and whether personality traits have any impact on the quality of the interpretation. Therefore, the aim of this book was to provide a scale which can help those people who love to be an interpreter or work as an interpreter to know whether personality traits have any influence in their work. It is hoped that applying such a personality scale for people who love to be interpreters can provide with a better diagnostic scale for a successful interpretation for those who are more likely to perform differently in different stages of the interpretation process. The purpose of the book was to investigate the relationship between extroversion/introversion and the quality of consecutive interpretation from English into Farsi.