Following the passage of "No Child Left Behind" ("NCLB") in 2001 and the reauthorization of the "Individuals with Disabilities Education Act" ("IDEA") in 2004, states adopted new policies regarding the education of students with significant intellectual disabilities. In the state of Delaware, these policy initiatives led to the creation of the Delaware Alternate Portfolio Assessment (DAPA) more than a decade ago. Through a cross-case analysis, this study explores the convergence of policymakers' and special educators' views regarding policy and instructional practices for students with significant intellectual disabilities. The qualitative analysis is informed by the Field Theory of Kurt Lewin and Leon Festinger's Theory of Cognitive Dissonance. The investigation of the relationship between policy and practice culminates in recommendations for future inclusion-related policies, the alternate assessment based on alternate achievement standards, and professional development for special educators who serve students with significant intellectual disabilities. [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.]