Previous papers have explored the concept of cognitive fidelity and its application to training in decision-making skills. These papers have described the concept of cognitive fidelity and its value in ensuring the realism of information as an essential factor in decision-making training. Devices designed for high cognitive fidelity would provide a user with highly realistic information, but might not require a physical environment of corresponding realism.

This paper reports on the design and development of a device for training the troubleshooting of an aircraft fuel system. The paper's initial focus is on the design choices made to ensure that cognitive fidelity remained high under conditions which sharply constrained physical fidelity. The paper shows how the functional requirements of specific training objectives were used as a basis for design specifications.

The development of the troubleshooting trainer is described, identifying the key design choices, and the way in which cognitive fidelity was used as the basis for selecting between specific design alternatives. Specific features examined include simulation of test procedures, simulation of related systems, and trainee interface.