Alternative Text Description for Fig. 3:

Figure 3 is a line graph, showing the change of the normalized and averaged time required for trainees to finish the picking work test. The x-axis represents the number of the trials. The y-axis represents the normalized and averaged time. The AVE1 shows the normalized and averaged data of trainees without PDA and the AVE2 shows those of trainees with PDA. The AVE1 goes horizontally and the AVE2 goes down as the number of trials increases.