Two different uses of interactive graphics in computer-assisted instruction are described. Interactive graphics may be used as substitutes for physical devices and operations. An example is simulation of operating on man/machine interfaces, substituting interactive graphics for controls, indicators, and indications. Interactive graphics may also be used to explicate invisible processes. Examples are interactive graphics that allow the student to initiate animations of physical processes and interactive block diagrams that allow the student to learn the functional organization of complex devices. Projects are underway to test the effectiveness of these uses. (Author)