The term closed loop-learning process refers to the idea that one learns by determining what s desired and comparing what is actually taking place as measured at the process and feedback for comparison. The difference between what is desired and what is taking place provides an error indication which is used to develop a signal to the process being controlled.

Harold Chestnut (1984) in: Lawrence P. Grayson, Joseph M. Biedenbach eds. Engineering--images for the future": proceedings, 1983 Annual Conference. p. 923