Transfer Effects

Care must be taken when designing controls and accompanying displays to avoid negative transfer effects. Negative transfer occurs when a user's prior experience and/or training conflicts with a new or current control or display design. Some of the earliest studies in human factors were concerned with these effects.

Early devices for flight training were simple devices that would bear little resemblance to today's simulators. One such early device was little more than a box with rudimentary rigging. Unfortunately, it was configured so that pushing the stick forward raised the nose of the "aircraft" and pulling the stick back lowered it. This was the reverse of the actual aircraft that trainees would fly. Pilots adjusted to the change initially, but in periods of crisis, some reverted to their initial training and crashed. Human factors psychologists determined the cause of these crashes to be negative transfer effects between the trainer controls and the controls in aircraft. Fortunately, Edwin Link developed the Link Trainer for pilot training. In 1934, the U.S. Army Corps purchased six for IFR (instrument flying) training. During WWII, over 10,000 were used to train over 500,000 pilots.

Link Trainer used for WWII Pilot Training