The purpose of this qualitative descriptive study was to explore how online female undergraduate STEM students at three higher education institutions in the southwestern United States described their academic self-efficacy in relation to the four sources of efficacy information. This study was theoretically supported by social cognitive theory (SCT) and consisted of a sample size of n=18 online participants. Participants were recruited through purposive, snowball, and convenience sampling. The overarching research question was: How do online female undergraduate students describe their academic self-efficacy? The sources of data were individual interviews with n=15 completed and an online questionnaire with n=16 completed. Data were analyzed inductively through Braun and Clarke's (2006) thematic analysis approach where the researcher synthesized descriptive data collected through interviews and the questionnaire. A codebook consisting of n=45 codes was developed to present and organize the codes (Appendix F). Through the thematic analysis process, 12 themes were identified: The findings of this study suggest that the sources of efficacy information do relate to their beliefs in their academic capabilities, but that they are not equal contributors to the development of academic self-efficacy. Increased peer interaction, feedback from instructors, and strategies to reduce negative feelings surrounding testing are needed. The researcher recommends future research with online STEM students in mathematics, physics, computer science, and engineering majors to further examine how academic self-efficacy relates to the sources of efficacy information. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]