TRACKING PERFORMANCE AS A FUNCTION OF EXPONENTIAL DELAY AND LEARNING

Eighty subjects performed a one-dimensional compensatory tracking task for 55 one-minute trials. The subjects were divided into five separate groups and each group performed the task with a different exponential delay between the control input and the display, a dot of light on a cathode ray tube. The time constants for the exponential delays were 0.015 seconds, 0.150 seconds, 0.900 seconds, 2.100 seconds and 3.000 seconds respectively. The results indicate that time-on-target scores decrease with increasing delay. For delays greater than 0.150 seconds, the decrease is linear. There is a sharper decrease in performance from 0.015 seconds delay to 0.150 seconds delay than for other portions of the function. Increased practice changes the level, but not the shape, of the total function. The effects of delay and learning were within the same range, indicating that a given level of system performance often can be achieved either by altering the delay or by training the operator. However, performance is maximized if delay is reduced and the operator is trained. (Author) Prepared in cooperation with Antioch Coll., Yellow Springs, Ohio, Contract AF18 600 50.