## 3 Experimental Results
When using the 2D & 3D mice together, the experimenters tended to have trouble controlling devices with both hands, resulting in incorrect clicks. Figure 6: Results from experiments on controlling KmodStudio in a virtual reality (VR) environment using different user interface devices (**a**) Total working time; (**b**) number of total clicks; and (**c**) click accuracy. In the case of using the Kinect sensor and the bend-sensing data glove, the experimenters often failed to click because they accidentally mis-clicked while bending their fingers or moving their wrists. In particular, for the VR controller, the experimenters often failed to click because the cursor moved a lot, even for slight movements in their wrists. In terms of total working time, when using the 2D & 3D mice together, the distribution of the experimenters varied. In contrast, when using the Kinect sensor and the bend-sensing data glove, most of the experimenters were close to the average value. The number of device clicks during the total operation showed a large variation between the experimenters using the VR controller, while the other three interfaces showed similar results overall. For click accuracy, various distributions were shown by the experimenters when using the VR Controller. It is considered that the VR controller showed a significant difference in learning level among the experimenters when learning the operation method during the training time (30 min provided for each interface device before starting the experiment). Finally, the Kinect sensor and the bend-sensing data glove had similar a learning level. Figure 7 shows the results of the survey on ease of learning, ease of use, immersion and fatigue. Regarding the ease of learning, the 2D mouse received the highest score (4.8). This was followed in order by the Kinect sensor and the bend-sensing data glove, the 2D & 3D mice and finally the VR controller. While the 2D mouse did not require any additional learning, the experimenters were considered to have difficulties in rotating objects on the actual software using the 3D mouse joystick when using the 2D & 3D mice together. Regarding the Kinect sensor and the bend-sensing data glove, the experimenters had difficulties in learning the control functions according to the finger bending motions listed in Table 1.  
Regarding ease of use, the 2D mouse also received the highest score. For the other three user interface devices, ease of use showed similar patterns to ease of learning. However, the score of ease of use for the VR controller were significantly different from those of the other interface devices. This is considered to be because the experimenters had difficulties in controlling the software using the VR controller. Figure 7: Questionnaire survey results for users controlling KmodStudio in a virtual reality (VR) environment using different user interface devices. (**a**) Ease of learning; (**b**) ease of use; (**c**) level of immersion; and (**d**) level of fatigue. Regarding immersion, the experimenters felt that while performing operations in the VR environment, the Kinect sensor and the bend-sensing data glove received the highest score followed by the VR controller. The 2D mouse and 2D & 3D mice combination received relatively low scores. These two interface devices received low scores for immersion because the experimenters used them on the desk while sitting on a chair, which limited their movements and resulted in a reduced immersion in the VR environment. In the VR environment, the fatigue that the experimenters felt for each interface device showed similar patterns to immersion. The experimenters showed high fatigue when using the Kinect sensor and the bend-sensing data glove and the VR controller, which they used while standing. It was found that the experimenters felt relatively low fatigue when using the 2D mouse and the 2D & 3D mice while sitting.