Educational institutions offering a master's degree program in instructional design incorporate instructional design theory into the master's degree course offerings. The responsibility for the student is to develop coursework. Master's degree learners will use instructional design theory to develop course materials. This study extends the knowledge of master's degree learners' selection and application of instructional design theory when developing coursework. The literature review identified few studies that have explored how, or if instructional designers apply learned instructional design theories, when designing instructional materials. An exploratory mixed methods study was conducted with forty-four master's degree learners from a public and a private university. Using double-loop learning as a framework for the study, participants provided the understanding of and selection of instructional design theory in developing coursework. The data analyzed resulted in findings which certify the importance of instructional design theory for master's degree learners. The findings include the familiarity with instructional design theories, what factors influence the selection and application of those instructional design theories. Results of the exploratory mixed methods study found how those theories are demonstrated in coursework materials. The study provided insights about the influences in the selection and application of instructional design theory. Recommendations for further research will enhance accredited educational organizations curriculum development for students of instructional design. [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.]