## 3 Results  
### Task Success Rate  
With the real prototype, the drilling experts achieved a mean success rate of 88 \(\pm\) 12% when performing the introductory tasks. With the VR prototype, the experts achieved a success rate of 87 \(\pm\) 14%, while the novices achieved a success rate of 87 \(\pm\) 17%. No significant differences were observed (\(p\) > 0.05). The success rates for each task are provided in the Supplementary Materials.  
Figure 4 presents the success rates of the tripping process. The drilling experts achieved a mean success rate of 91 \(\pm\) 13% with the real prototype. For the VR prototype, the experts scored a mean success rate of 91 \(\pm\) 12%. The novices achieved a mean success rate of 76 \(\pm\) 18% with the VR prototype. The difference between drilling experts and novices in the mean success rate for the VR prototype was significant (\(p\) = 0.006). The definitions of the individual tasks can be found in the Glossary.  
\begin{table}
\begin{tabular}{c l} \hline \hline
**Category** & **Question** \\ \hline \multirow{4}{*}{General operation} & How do you evaluate the operation? \\  & Which functions are you missing? \\  & Are there functions that would not be directly accessible during \\  & safety-critical moments? \\  & Would you prefer this concept to the previous operating concept? \\ \hline \multirow{4}{*}{Touchscreens} & How do you like the touchscreens? \\  & Could you read everything on the touchscreens? \\  & Do the touch fields have an appropriate size? \\ \hline \multirow{4}{*}{Control elements} & How do you like the control elements on the side consoles? \\  & Are there any physical control elements that you would prefer to have \\  & implemented as touch functions? \\  & Are there touch functions that you would prefer to have implemented as \\  & physical control elements? \\ \hline \multirow{2}{*}{Iron roughneck} & How do you rate the control of the iron roughneck via the touchscreens? \\ \hline \multirow{2}{*}{Indicators} & How do you rate the indicator screen? \\  & Could you read indicators correctly? \\ \hline \hline \end{tabular}
\end{table}
Table 3: Interview questions.  
Moreover, Figure 4 shows that experts had issues with the same tasks in both the VR and real prototype environments. For example, experts were sometimes unable to extend the iron roughneck (IR) and adjust its height in both VR and reality (Tasks 7 and 8). An iron roughneck is a machine used for screwing and unscrewing a drill string. Several novices had issues in Tasks 9-15. The experts had no difficulty in performing these tasks.  
Figure 5 lists the success rates of the simulation of the top drive connection process. The experts achieved a mean success rate of 94 \(\pm\) 5% with the real prototype. For VR, the experts achieved a success rate of 95 \(\pm\) 9%. The novices achieved a mean success rate of 84 \(\pm\) 19%. There were no significant differences (\(p\) > 0.05).  
The success rates for the second tripping attempt are shown in the Supplementary Materials (Figure S6). The experts achieved higher success rates in the second tripping attempt, and consequently made fewer errors (M\({}_{\rm Real}\) = 93 \(\pm\) 8%; M\({}_{\rm VR}\) = 95 \(\pm\) 9%) in both VR and reality. This difference was not statistically significant (\(p\) > 0.05). The novices had significantly higher success rates in the second tripping process (\(p\) = 0.048; M\({}_{\rm VR  
Figure 4: Comparison of the success rates for the simulation of the tripping process. The bars indicate the relative frequencies of the evaluation levels (green = good, yellow = medium, red = poor).  
Figure 5: Comparison of success rates for the simulation of the top drive (TD) connection process. The bars indicate the relative frequencies of the evaluation levels (green = good, yellow = medium, red = poor).