Table 1. Mean values and standard deviations of the estimations in the respective points in time.

	t 1	t 2	t 3	t 4
Handling	7.1 ± 2.07	8.27 ± 1.5	8.02 ± 1.32	8.08 ± 1.17
Work safety	5.78 ± 2.03	7.02 ± 1.77	7.17 ± 1.53	7.61 ± 1.19
Time efficiency	7.71 ± 1.49	8.63 ± 1.38	8.43 ± 1.11	8.4 ± 1.32
Overall impression	6.05 ± 1.78	7.36 ± 1.68	7.43 ± 1.4	7.86 ± 1.39