An Instructor Operator Station (IOS) is an interface that provides instructors with controls for training environments and can include capabilities for scenario development, exercise control, performance measurement, and debriefing. This chapter provides a primer on the purpose and function of IOSs, including the importance of instructional strategies for guiding the structure of the technology that makes up the IOS. It addresses lessons learned in the development of IOS functionality, including the integration of emerging technology, modularity in development, and human factor concerns. The chapter also addresses what an IOS is, why it is important, and what lessons have been learned through past IOS research and development. It discusses instructional strategies and provides their importance as the guiding influence for IOS technology selection and development. While exercise control subsystems may include artificial intelligence to support instructorless training, the chapter focuses on aiding instructors in providing training.