This volume presents an object-oriented approach for developing interactive graphical device models and for delivering instruction and performance aiding with such models. The volume attempts to illustrate, via a series of examples, why and how the particular design given satisfies relatively intensive and diverse instructional and performance-aiding demands with surprising ease. The early chapters focus on the fundamental design concepts upon which all applications stand, including a consistent design of the basic elements - objects - from which all models are produced; a clear separation between the model of the target domain and the instructional processes; and, wherever possible, automatic generation of user interactions, based on the structure and content of the model. Each of the later chapters focus on one particular application area, including explication of complex system functions, diagnostic instruction and guidance, procedural guidance, scenario-based instruction, and...