Few studies have explored the positive characteristics that motivate doctoral students to pursue and complete their degree; research has historically focused on doctoral student attrition. To fully understand doctoral student success, research must focus on factors that contribute to completion. Based on Seligman's theory of explanatory style, this quantitative research was designed to determine the relationship between explanatory style and doctoral study retention and whether an optimistic explanatory style is related to continuance in degree program. A quasi-experimental design was implemented and used an online survey with a cross-sectional convenience sample. Participants provided demographic data and completed the Attributional Style Questionnaire. A two-factor analysis of variance was used to discern differences in optimistic explanatory style (a) at various stages of doctoral study and (b) between programs of study. Results indicated that there was no significant relationship between explanatory style and either time in the doctoral program or the degree program itself. Recommendations for action include surveying a larger sample from a more diverse population, perhaps across several universities, online and traditional. This study is an additional opportunity to add to positive psychology's continued growth. It presents an opportunity to explore other positive characteristics that contribute to successful completion. One avenue this study promotes positive social change is encouraging universities and institutions to better understand their students, tapping into those students' optimistic qualities, while continuing to discover additional characteristics in an effort to increase retention and successful graduation. [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.]