## 5 Discussion
### Accessibility Recommendations
The results of data analysis show that indirect interaction, such as the use of a slider, is more intuitive and accessible and enables more precise and efficient manipulation of 3D objects than direct interaction. The sublevel with indirect interaction using a slider has a shorter task execution time than the sublevel with direct interaction with a 3D object. Although one might expect direct interactions to be more efficient and \"natural\" for participants, the results indicate the opposite. Participants rated the ease of rotating the 3D object and satisfaction with the precision achieved slightly higher in the sublevel with indirect interaction. This result can be explained by the fact that most participants do not have prior experience with 3D interactions, and the gesture recognition technology currently in use is not yet mature enough to ensure natural and intuitive direct interaction. This points to the importance of clear and intuitive UI elements for 3D interactions, especially when learning new skills or tasks, and suggests that improving gesture recognition technology could increase the effectiveness of direct interactions in the future. **Recommendation 5:**_Users should be able to use different UI elements according to their preferences and be able to add or remove these elements via the accessibility settings._  
The last parameter analyzed was the size and distance of interaction elements on the UI. The data analysis in the research showed that larger buttons and appropriate spacing allow for a balance between ease of pressing and precision, thus reducing user frustration. This is consistent with Fitts's Law, which states that the time required for a targeted action depends on the distance to the target and the size of the target. The size of the button, 0.24 \(\times\) 0.1676, and the distance of \(-\)10 spatial units allowed users to interact more easily and accurately, resulting in less frustration and greater user satisfaction. **Recommendation 6:**_For tasks that require speed and efficiency, larger UI elements and an optimal distance between these elements and the virtual hand should be used according to [PERSON]'s law. For tasks that require precision, it is important to find a balance between the size of the UI elements and their distance from the virtual hand, where a smaller distance can reduce the difficulty users could have in accessing smaller UI elements._  
The implementation of the proposed accessibility recommendations has the potential to improve both the usability and inclusivity of XR applications. Central to this is the idea that all accessibility features should be closely aligned with the primary goals and intended purpose of the software. Maintaining consistency of interaction design across different levels and task types reduces cognitive load and allows users to form stable mental models. This, in turn, improves task performance and reduces the likelihood of errors. Building on this, the research findings on the optimal size ratio between virtual 3D objects and the user's virtual hand provide practical guidance for interaction design. These ratios can serve as a basis for manual sizing of objects in static systems or as baseline values in systems with automatic scaling based on object context. In addition, using [PERSON]'s law to determine the optimal size and spacing of UI elements can lead to measurable improvements in interaction efficiency, especially in time-critical scenarios. This study also emphasizes the differentiated role of distracting visual elements. While such elements have a negative impact on performance in tasks under time pressure, they can promote engagement and concentration in longer or monotonous tasks without time pressure. This result underlines the importance of giving users control over their interface environment. In this context, customizability proves to be a crucial aspect of inclusive design.