This study examines the practices of an instructor who designed and instantiated an online professional development program to foster expertise in online instructional design. The main purpose of this study is to investigate how her application of technological affordances may inform a re-examination of Cognitive Apprenticeship (Collins, Brown, & Newman, 1989). This theory was formulated to guide the design and research of a workshop-based learning environment that support students in thinking, problem-solving and accomplishing tasks like practitioners in the field. Since the theory was proposed prior to the advent of online teaching and learning, there is a need to reconsider how it can be modified, given the evolution of online tools in the last decades. Evidence reveals that the instructor's leveraging of technological affordances is fundamental in understanding modifications that need to be made. Her practice compels us to reconsider how online affordances can enable a multi-focal and personalized approach in helping learners develop theoretical knowledge. Her practice also demonstrated how online technological tools were critical in bringing models into the online environment, who then broadened conceptual categories of modeling to include "macro-models" such as theoretical concepts, practices, and even an instructor's entire practice. Core CA concepts like visible thinking were amplified through the use of technological affordances that provided access into both instructors' and students' thinking processes. Evidence also foregrounded how audio and video tools enabled personalized asynchronous guidance at critical junctures of students' development. The combined evidence suggests that, with modifications that take into account the use of online affordances, Cognitive Apprenticeship is contemporary and relevant when re-contextualized within the professional development of adults through online instruction. [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.]