Disproportionate representation of historically underserved students in advanced placement programs, such as the IB program, is a persistent issue nationwide. Despite being called "the great equalizer," public education often perpetuates systemic inequities for marginalized students, including those living in poverty or belonging to racial minority groups. While the student population in public schools is becoming increasingly diverse, advanced course programs are evolving more slowly, and enrollment remains dominated by students from already advantaged backgrounds, such as middle-class white households. This study uses intersectionality theory to analyze three possible methods of enrollment or referral--self-referral, parental request, and faculty recommendation--providing a deeper understanding of this issue. This mixed-methods action research study implemented an innovation aimed at enhancing faculty self-efficacy and attitudes toward communicating about the IB program and referring students for enrollment. The study was guided by two theoretical frameworks: the Conceptual Change Model and Guskey's Model of Teacher Change, which emphasize the role of teacher self-efficacy in driving change. The innovation, a professional development workshop, aimed to facilitate conceptual change by encouraging participants to recognize their preconceptions about the IB program and to either build on accurate prior knowledge or replace misconceptions with more accurate and comprehensive 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.]