## 3 Results and Discussion
### Effect of the Navigation System and Signage System on Perceptual Conflict  
This study employed the SSQ and measured the participants' performances in three dimensions, namely, oculomotor, disorientation, and nausea, before and after the experiment to determine whether they exhibited the main symptoms of cybersickness. The results indicated that the SSQ scores of the middle-aged and older participants increased after the experiment; their mean scores increased by 1.465 points (\(t\) = 4.776, \(p\) = 0.000). Therefore, after browsing the 3D virtual store for a while, some cybersickness symptoms were induced in the middle-aged and older participants. Additionally, the two-way ANOVA results indicated that the effect of the navigation system on the participants' perceptual conflict was significantly different (F = 14.241, \(p\) = 0.001). The effect of the signage system on the participants' perceptual conflict was not significantly different (F = 10.696, \(p\) = 0.003). The interaction between the navigation system and the signage system was also not significant (F = 1.582, \(p\) = 0.223) (Figure 8). To understand whether the effect of the cross-zone navigation system was better than that of the map navigation system on perceptual conflict, a \(t\)-test was performed. The results indicated that the cybersickness scores of the cross-zone navigation group were significantly lower than those of the map navigation group; the mean score was 1.402 points lower (\(t\) = \(-\)3.044, \(p\) = 0.006). The participants in the cross-zone navigation system group from the catalog directly jumped to the target section, quickly found the required products, and avoided having to pass through the aisles multiple times to search for products. The system decreased their exposure to the VR environment, preventing them from experiencing spatial disorientation and perceptual conflict in the 3D virtual store. The participants in the map navigation group were required to repeatedly pass through the aisles in the 3D virtual store. Although this enabled them to develop their spatial perception ability, it also increased their risk of perceptual conflict. The cross-zone navigation system guided the participants to quickly reach the desired positions of the target products, thereby preventing spatial disorientation and other problems caused by unfamiliarity with the 3D VR environment. Additionally, if the participants lost their spatial orientation from improperly operating the system, they could quickly correct their spatial position by using the catalog on the tablet computer. This was one significant advantage of the cross-zone navigation system. Therefore,  
H3 was accepted. In signage, the results showed a significant difference between with and without the signage system on perceptual conflict. A \(t\)-test was performed. The results indicated that the cybersickness scores of the group in the 3D virtual retail store with signage were  
Figure 8: SSQ scores for map-based navigation and cross-zone navigation groups. significantly lower than those without signage; the mean score was 1.216 points lower (\(t=-2.862\), \(p=0.007\)) (Figure 9). The reason may be that the purpose of the signage system was to inform the participants of their position and destination and to provide details regarding target products. Additionally, the signs prevented the participants from idling, taking wrong turns, and straying from the correct path. [PERSON] et al. (1997) [25] found that sickness symptoms were shown to increase in participants exposed to a drum rotating at 60\({}^{\circ}\)/s around its vertical axis. [PERSON] et al. (1990) [26] reported that rotation speeds ranging from 10\({}^{\circ}\)/s to 200\({}^{\circ}\)/s around the lateral axis of an optokinetic projection of random dots resulted in a vection sensation after 3-8 s of exposure. Therefore, a virtual scene's incorrect movement might be a critical factor inducing cybersickness in a 3D virtual retail store.