# 3D User Interface Design and Usability for Immersive VR
## 5 Results and Data Analysis
### Summary and Findings  
Table 12 shows the answers of the interface ranking for the most suitable interface for 3D desktop in VR environment by the participants. The average ranking was calculated as follows, where: w = weight of ranked position, x = response count for answer choice. \[\text{Average ranking}\ =\ \ \frac{\text{x}_{1}\text{w}_{1}\ +\text{x}_{2}\text{w}_{2}\ +\text{x}_{3}\text{w}_{3}\ \dots\ \text{x}_{n}\text{w}_{n}}{\text{Total response count}}. \tag{2}\] \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multicolumn{1}{c}{\multirow{2}{*}{**Success of Scenario Completion**}} & \multicolumn{2}{c}{**Pointer**} & \multicolumn{2}{c}{**Controller**} & \multicolumn{2}{c}{**Gesture**} \\ \cline{2-7}  & **Standing** & **Seated** & **Standing** & **Seated** & **Standing** & **Seated** \\ \hline
**Easily completed** & 90.48\% & 85.71\% & 71.43\% & 85.71\% & 90.48\% & 76.19\% \\
**Completed with difficulty/help** & 9.52\% & 14.29\% & 28.57\% & 14.29\% & 9.52\% & 23.81\% \\ \hline \hline \end{tabular}
\end{table} 
Table 11: Participants’ success levels for completing the scenario. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multicolumn{1}{c}{\multirow{2}{*}{**Point-and-Click UI**}} & \multicolumn{2}{c}{**Controller-Based DM UI**} & \multicolumn{2}{c}{**Gesture-Based UI**} \\ \hline First & 11 & 5 & 5 \\ Second & 8 & 9 & 4 \\ Third & 2 & 7 & 12 \\ Average Ranking & 2.43 & 1.90 & 1.67 \\ \hline \hline \end{tabular}
\end{table} 
Table 12: Interface ranking by participants. The first choice has a weight of 3, the second choice has a weight of 2, and the third choice has a weight of 1. As seen in the table above, the point-and-click interface has the largest value for average ranking, therefore it is the most preferred UI according to user feedback, followed by the controller-based interface as the second highest choice and finally the gesture-based interface as the third highest choice. The ranking in Tables 12 and 13 shows that the most suitable interface for the desktop VR environment chosen by participants was the point-and-click UI (57.14%), followed by the gesture-based interface (33.33%), and finally the controller-based UI (9.52%). User's familiarity with the point-and-click interface can be one reason for being the most preferred interface by the participants for the desktop on VR. The percentage for the gesture-based interface shows a promising capability for utilizing the gesture as an interaction mode in the desktop VR. The reason for the lowest percentage for the controller-based interface could be that most of the users are not familiar with controller's device, in addition to the short training given. Although the previous results show that the point-and-click UI is the most preferred interface for the desktop in VR from the participant's point of view, a further analysis reveals that participants are still preferring to perform some certain tasks using the other interaction modes. For example, as seen in Table 14 they prefer to perform the scale task using the controller-based interface, but the gesture-based to display the menu. For each task available in the 3D UI, its corresponding preferred interface from a participants' point of view are as follow:  
* Close: Both point-and-click UI and gesture-based UI (42.86%). * Open: Point-and-click UI (57.14%). * Scroll: Point-and-click UI (47.62%). * Scale: Controller-based UI (38.10%). * Delete: Point-and-click UI (52.38%). * Duplicate: Point-and-click UI (61.90%). * Display the menu: Gesture-based UI (52.38%). Table 15 shows that 52.38 % of the participants prefer to keep the interaction simple in the 3D UI for the desktop in VR using one interaction mode only. While 47.62% prefer to implement a hybrid approach by combining the gesture-based interaction and physical-device based interaction. The results are very close and point towards a hybrid approach as future research.