Abstract:
Experimental measurements of human controller performance have been made during extended periods of practice in visual sine-wave tracking tasks. It has been found that, irrespective of task difficult, RMS error scores decreased to such small magnitudes that differences in scores due to different task variables would have no practical significance. Thus the averaged values of steady scores when tasks are well learnt are meaningless for subject or task difficulty comparisons. It has been shown that the performance scores vary in an exponential manner with the number of task repetitions and it is proposed that an empirical constant related to the rate of decrease of scores be used as a measure of relative task difficulty.
