## 3 Results and Discussion
### Overall Comparative Analysis  
This study aimed to develop a cross-zone navigation system and a signage system for 3D virtual retail stores to provide middle-aged and older consumers with high-efficiency navigation for finding products. According to the results of the previous discussion, the group that used both the map-based navigation system and the signage system had the highest spatial perception scores, but the group that used both the cross-zone navigation and signage systems had the lowest SSQ scores. Therefore, there was a substantial effect of combating cybersickness on the combined cross-zone navigation-signage system. In the SSQ analysis, there were three distinct symptom clusters labeled oculomotor (O; eyestrain, difficulty focusing, blurred vision, headache), disorientation (D; dizziness, vertigo), and nausea (N; nausea, stomach awareness, increased salivation, burping) [19]. To further understand the effect of the cross-zone navigation system and the signage system on combating different symptoms of SSQ, a comparative study was performed, as shown in Figures 12 and 13. Figure 12 shows that participants' average SSQ subscores (oculomotor, disorientation, and nausea) increased after the experiment. However, the SSQ subscores of the combination of map-based navigation without signage increased significantly, especially for oculomotor activity. The SSQ subscores of the combination of cross-zone navigation with signage increased insignificantly. In fact, the study of [PERSON] et al. (1993) showed that a high oculomotor score was most likely due almost entirely to some property of the visual system. Therefore, as long as an individual is operating in a virtual environment, oculomotor symptoms may inevitably occur. In Figure 13, it can be seen that oculomotor activity increased in different navigation combinations, but the combination of cross-zone navigation with signage had the smallest increase. The scores for disorientation and nausea did not increase. This showed the effectiveness of the cross-zone navigation and signage systems developed in this study in combating cybersickness, especially on the two symptom clusters of disorientation and nausea. In object-seeking, Figure 14 shows a box-and-whisker plot of object-seeking times for four different system combinations. The results showed a significant difference between the map-based and cross-zone navigation systems (\(t=12.957\), \(p=0.000\)). The group that used the map-based navigation system with or without a signage system spent more time seeking target objects. Because of exposure to the virtual environment for a long time, these groups could easily induce cybersickness. The cross-zone navigation system assisted the participants in seeking target objects quickly. Shortening the time to seek the object was also the primary reason for reducing the occurrence of cybersickness, as discussed in the previous paragraph. Additionally, there was a significant difference between map-based navigation systems with and without signage (\(t=2.905\), \(p=0.017\)). It also explained the importance of signage for map navigation. Figure 12: The average SSQ subscores of different system combinations on three distinct symptom clusters (oculomotor, disorientation, and nausea). Finally, in system utilization, Figure 15a shows the CPU and GPU performances when a participant used the map-based navigation-signage system to seek one target object. Figure 15b shows the performance of another participant using the cross-zone navigation-signage system to seek the same object. For the moment of space crossing, the CPU utilization had a peak (Figure 15b red circle in the CPU utilization) in the cross-zone navigation-signage system, but the GPU utilization was lower than the map-based navigation-signage system. Figure 14: Box-and-whisker plot of object-seeking times for four different system combination groups. Figure 13: The results of different system combinations on the increase in average SSQ subscores (oculomotor, disorientation, and nausea) after the experiment.