## 3 Results
### Semi-Structured Interview on Satisfaction with the Prototype  
Both the VR drilling experts group and the real drilling experts group rated the operation positively overall (Question 1). Seven of the eight VR drilling experts preferred the new concept to the previous operating concept. The real prototype was preferred by six out of eight experts. One expert preferred the previous operating concept. One expert each in VR and in the real world preferred neither the new nor the old operating concept.  
All the participants stated that the control elements had an appropriate size. In response to the question \"Which functions are you missing?\", six participants who tested the VR prototype answered \"none\". One participant wanted to see the blowout preventer controls. The participants who tested the real prototype missed a switch to turn the hoist on and off, an emergency stop button, and an indicator of the equipment status. Half of the participants in this group stated that no functions were missing or that they would only be able to answer the question once they had tested the system for a longer period.  
Seven of the eight participants testing the real prototype complained that the IBOP was not available quickly enough in safety-critical moments. In the virtual test, this was criticized by only two participants.  
Regardless of the prototype tested, all participants rated the touchscreen positively. The text and images could be read easily by all the participants in both the real and VR prototypes, and the size of the touchscreen was rated as sufficiently large.  
There were differences in the response behaviors between the groups, particularly in questions regarding the control elements. The question \"how do you like the control  
Figure 9: Mean number of interactions and 95% confidence intervals for completing each test scenario. Significant differences (\(p\) < 0.05) are marked with an asterisk (*).  
elements on the side consoles?\" was answered positively by all participants for the VR prototype. Participants liked the clarity of the consoles. Specific control elements and their positions were criticized in isolated cases. The participants who tested the real prototype were also satisfied with the design and clarity of the side consoles. However, individual control elements were discussed and criticized more intensively.  
Control of the iron roughneck was rated good by all participants. In both the VR and physical prototypes, individual participants doubted the feasibility of the new control concept for the iron roughneck.  
Regardless of the prototype tested, the front screen and indicators displayed on it were rated positive. In both VR and reality, the most frequent responses referred to the drillometer (a central indicator for monitoring a hook load). In both groups, 50% of the participants preferred a larger drillometer with more sensitive and larger pointers.  
From the interviews with the participants who tested the real prototype, 13 optimization potentials were identified in expert workshops, such as an optimized layout of controls, indicators, and the design of menu structures. Eight optimization potentials were identified from interviews with the VR participants.