According to a report released in 2005, titled "Rising Above the Gathering Storm," there is a critical priority to develop, recruit, and retain top students, scientists, and engineers to maintain U.S. economic competitiveness in response to rapid globalization. To improve our global competitiveness, the U.S. must retain individuals from diverse backgrounds within science, technology, engineering, and mathematics (STEM) fields. Unfortunately, too few students from underrepresented backgrounds are continuing throughout the STEM educational pipeline. A number of scholars have suggested that students often leave the STEM fields due to conflicts they experience between their emerging identity in science and the other core identities that shape who they are and how they view themselves. For instance, students of color and women often describe science environments with chilly climates for diversity, where instances of overt or covert discrimination are commonplace. The narrow culture of science and the decontextualized nature of science education can also discourage women and students of color because it requires students to detach themselves from any personal interest or relationship they had with science concepts in order to remain rational and objective. In addition, for many first generation college students, it is often critical for them to maintain prior relationships from their home communities, but they can experience difficulties communicating the value and benefits of scientific pursuits to less educated friends and family members. In such cases, these individuals experience tensions between science and their social identities as people of color, women, and first generation students. Whether they persist is influenced by how they are able to negotiate this tension in order to maintain a sufficient sense of identification with the sciences. The results of this study indicated that students adopted specific strategies to manage and negotiate tensions between their social identities and science identities. Among these strategies, it was found that students were able to redefine or reconstruct their own meanings of what it meant to be a scientist and a person of color. Students also developed ways to simplify science in order to make it more relevant and accessible to non-science friends and family members. An additional strategy students commonly utilized was wearing multiple hats, or managing different identities for each given context or situation. By shifting the emphasis or salience of their science identity between science and non-science contexts, students were able to delicately balance seemingly oppositional identity frameworks. For this dissertation, I examined underrepresented racial minority (URM) students, who successfully persisted and enrolled in graduate STEM degree programs, in order to understand the process of science identity development. Focus group interviews were conducted with STEM graduate students during site visits to six campuses across the United States. Students at the graduate level were targeted because they could offer insights regarding the key experiences that permitted them to successfully transition through early education and college to become research scientists in graduate school. The campus sites included two Hispanic serving institutions (HSI), one historically Black college/university (HBCU), and three predominantly White institutions (PWI). These institutions were selected based on their high rates of STEM degree completion among URMs. The proposed study will draw from this focus group data. This study employed a phenomenological approach to specifically capture the lived experiences of students who have successfully navigated the scientific pipeline. I investigated whether students experience conflicts between their emerging science identity and other core identities. For students that do experience identity conflicts, it was important to observe how these conflicts were negotiated in order to maintain a healthy sense of science identity. By identifying strategies that students employ to successfully persist in STEM fields, this study can inform educational practices and programs to support students from diverse backgrounds. Accordingly, this dissertation topic has future implications for issues that are of growing importance in STEM fields, such as experiential learning, interdisciplinary collaboration, and the link between science and social change. The second implication of this study is that it will address misconceptions of race and gender as a deficit in science by examining the role of student agency in successfully negotiating identity conflicts in academic contexts. [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.]