Although many intelligent tutoring systems have made use of interactive graphical models of topic matter, most have been developed using conventional programming tools, sometimes augmented by special interface editors. This approach permits a high degree of flexibility and control, but its successful application requires a great deal of technical skill and development time. It is therefore feasible for only a small subset of the training and instruction contexts in which an interactive simulation would be of benefit. Recently, several authoring environments have been developed that support the creation of interactive graphical models by direct manipulation. IMTS, RAPIDS n, and RIDES are three authoring tools for the production of intelligent tutoring systems centered around interactive graphical models. The experience of developing these three authoring environments and applying them to produce a number of tutors has helped to clarify the desirable features for authoring systems for interactive graphical models.