From 1946 to 1962, within the fields of military and applied psychology, a methodological shift occurred concerning how to best design synthetics
(training aids and devices) to facilitate training transfer
(the application of skills acquired in a synthetic environment to a real operational situation). During this period, the work of the military psychologists Charles Osgood, Robert Gagné, and James Gibson was crucial to destabilizing the long held transfer theory of “identical elements” which necessitated direct, observable, correlations between the training and performance environments. This principle had originated in the 1901 studies of the educational psychologist Edward Thorndike and had held an inordinate influence over design and operation of training devices and programs in the military over the previous 40 years. Using the principle of identical elements
as its origin, this history progresses from superficial resemblance, the common-sense standard of physical fidelity, through structural resemblance, the less apparent, but more efficient feature of functional fidelity, and culminates in the perceptual resemblance of psychological fidelity, which allowed for more oblique representational modes to emerge.