For the past several years, the authors have been studying the impact of prior experience on performance in introductory Information Technology (IT) courses. Since 2002, data has been collected on all incoming freshmen and performance has been measured by the grade received in initial courses. The grades are expressed in the traditional four-point scale used at most US colleges and universities. Prior studies (Holden & Weeden, 2003, 2004, 2005) have used an experience index to determine the level of prior experience possessed by students entering the IT undergraduate program. The index has also been used to place students in appropriate classes. This study looks at the components of the formula used to calculate this index as well as some informal experience information that is collected as part of the survey. It concludes with a revised version of the experience index formula which will be used to place students into cohorts in the future.