# A Study on Visually Induced VR Reduction Method for Virtual Reality Sickness
## 3 Results  
In this section, we analyze the experimental results to confirm the effectiveness of the proposed VR sickness reduction methods and discuss. First, using the Shapiro-Wilk test, we confirmed that all measured SSQ data satisfy the normal distribution. Then, SSQ measured in the original video (V0) without VR sickness reduction method and SSQ measured in videos with VR sickness reduction method used (V1-V5) were compared by the paired \(t\)-test. Nausea score was significant when the M1 was used (\(p\) = 0.042): nausea was reduced by 36%. When the other VR sickness reduction methods (M2-M5) were used, nausea was not significantly reduced. From this result, it was confirmed that a continuously expressed VG without movement significantly reduces nausea. Oculomotor discomfort score was not significant in any VR sickness reduction methods (M1-M5). Since the proposed methods (M1-M5) were a method to reduce VR sickness by inducing the user's gaze, it could not confirm the effect of reducing oculomotor discomfort. Disorientation score was significant when the M1 (\(p\) = 0.019), M2 (\(p\) = 0.002), and M4 (\(p\) = 0.048) were used: disorientation was reduced by 33%, 43%, and 30% in M1, M2, and M4, respectively. From these results, most proposed methods were confirmed to reduce disorientation. Total score was significant when M1 was used: total score was reduced by 29%. From these results, it was confirmed that the M1 was only method to reduce VR sickness level overall. Table 2 shows a comparison of VR sickness reduction effects. Figure 8 shows a graph comparing SSQ score of VR sickness reduction methods. M1 showed the greatest reduction in nausea, disorientation, and total score (Circle in Figure 8). Furthermore, M2 and M4 showed significant reduction in disorientation (Circle in Figure 8). Other VR sickness reduction methods such as M3 and M5 did not show significant reduction effect. Therefore, it was confirmed that the most effective method for reducing VR sickness is M1. Additionally, we analyzed SSQ results of M0 and M1 using paired \(t\)-test to confirm the difference in the level of VR sickness depending on gender (M0: no VG; M1: most effective method). The analysis results show that the difference between the genders was not significant. Table 3 shows the difference in the level of VR sickness depending on gender. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Method**} & \multicolumn{8}{c}{**SSQ**} \\ \cline{3-8}  & \multirow{2}{*}{**Nausea (N)**} & \multicolumn{2}{c}{**Oculomotor**} & \multirow{2}{*}{**Discomfort (O)**} & \multirow{2}{*}{**Disorientation (D)**} & \multirow{2}{*}{**Total Score (T)**} \\  & & & & & & & & \\ \cline{3-8}  & \multirow{2}{*}{**Score**} & **Rate** & \multirow{2}{*}{**Score**} & **Rate** & \multirow{2}{*}{**Score**} & **Rate** & \multirow{2}{*}{**Score**} & **Rate** \\  & & **(\(p\)-Value)** & & & & & & **(\(p\)-Value)** \\ \hline M0 & 13.36 & \(-\) & 21.41 & \(-\) & 26.45 & \(-\) & 22.91 & \(-\) \\ M1 & 8.59 & \(-\)36\% & \(16.30\) & \(-\)24\% & \(17.75\) & \(-\)33\% & \(16.18\) & \(-\)29\% \\ M2 & \(11.93\) & \(-\)11\% & \(19.33\) & \(-\)10\% & \(14.96\) & \(-\)43\% & \(18.23\) & \(-\)20\% \\ M3 & \(10.49\) & \(-\)21\% & \(17.43\) & \(-\)19\% & \(-\)19\% & \(-\)13\% & \(10.27\) & \(-\)9\% \\ M4 & \(13.12\) & \(-\)22\% & \(19.71\) & \(-\)8\% & \(18.44\) & \(-\)30\% & \(19.82\) & \(-\)13\% \\ M5 & \(12.40\) & \(-\)7\% & \(19.52\) & \(-\)9\% & \(18.79\) & \(-\)29\% & \(19.54\) & \(-\)15\% \\  & & (\(0.775\)) & & & (0.606) & & (0.115) & & (0.425) \\ \hline \hline \end{tabular} \({}^{t}\)_p \(<\) 0.05. **\(p<\) 0.01._  
\end{table} 
Table 2: VR sickness reduction method used in experiment. From the results of the fatigue questionnaire response, M4 was shown to be the most fatigue causing method. From the results, M4 was confirmed to be effective in reducing disorientation, but it was also confirmed that this method caused the most fatigue in subjects. In addition, M3 was confirmed to have the second highest fatigue score.