Depth and Complexity a set of prompts or concepts, represented an approach to curriculum differentiation for gifted students, that originated from a California Department of Education (1994) document describing educational needs for gifted students. Derived from three sources: (1) a review of Advance Placement curriculum and assessment, (2) a study of California Golden State Exam requirements, and (3) conventional wisdom about the accelerated needs of gifted students and the nature of academic disciplines, the prompts of Depth and Complexity have been integrated as a G.A.T.E. standard (CDE, 2005). While they were designed to create learning experiences that nurture excellence and develop expert-practice among gifted students, a study demonstrating how the 11 prompts of Depth and Complexity were relevant and applicable to academic disciplines had yet to be conducted. Findings from this study explored the concepts of Depth and Complexity and described their relationship to the academic disciplines. This qualitative study of experts' scholarly work provided content validity for the use of the concepts of Depth and Complexity as a viable approach to differentiate curriculum for gifted students. Experts across academic disciplines qualified for participation in this study based on a set of criteria: (1) they possessed a terminal academic degree, and (2) had at least 10 years of experience in a respective field. A multi-level interview protocol was used to gather information for analysis and yielded responses about the relationships of the concepts of Depth and Complexity to academic disciplines. The results of the study indicated that the concepts of Depth and Complexity were applicable for and relevant to academic experts and their disciplinary work. The significance of this study lies in the implication that the concepts of Depth and Complexity were therefore an appropriate and authentic means to facilitate content knowledge in the study of the disciplines for gifted students. [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.]