Reports consistently demonstrate that the attainment of a high school diploma is not simply of value to the individual student, but that the benefit of a high school diploma is reaped by the graduate's community as well. Most educators readily acknowledge the importance of dropout prevention and the significance of a high school diploma. A corresponding issue is the accuracy with which dropout and graduation rates are calculated. This policy brief examines various calculation methods, the history behind the use of particular methodologies, and the strong nationwide trend toward a cohort rate. The report also examines Indiana legislation that has shaped the Indiana graduation rate methodology. Advocacy for a uniform national methodology is also discussed. Five web resources are included. (Contains 37 endnotes and 3 tables.)