Many students do not graduate from high school, which could lead to poorer quality of life, lower paying jobs, and increased crime. Previous researchers have indicated that Hispanic and African American students graduate at a significantly lower rate than White students. However, there remains an important gap in the current literature regarding high school graduation and variables such as school attendance, school involvement in sports and clubs, ethnicity, and special education. Therefore, the purpose of this study was to identify variables among all students which may be related to an increase in high school graduation rates. The study is based on social identity theory, which focuses on individuals' desires to be part of a group. Data from 618 12th-grade students of multiple ethnicities attending a comprehensive high school during the 2008/2009 school year were examined. Students' school absences, involvement in high school sports or clubs, ethnicities, and special education placement were collected from school records. Discriminant function analysis was used to identify the predictive value of each of these variables on high school graduation. Findings from this research indicated that, for all groups (Caucasian as well as minority groups), increased participation in sports and clubs and decreased school absences are crucial to increasing high school graduation rates. This is an important contribution to the existing literature and can contribute to social change initiatives through the knowledge of variables that increase high school graduation rates and lead to greater postsecondary options, such as military service, trade schools, community colleges, and universities. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]