## 5 Discussion
### Conclusions  
This study investigated the characteristics of different VR types and analyzed their advantages to derive design recommendations. Through a comparative analysis of freeform creativity and goal-directed training VR across various metrics, including emotional responses, usability, flow experience, technology acceptance, preferences, and satisfaction, the present study revealed significant differences. The findings underscore the potential for crafting activities that foster autonomous user engagement in activities and a beneficial overall VR experience. The conclusions of this study are as follows. Shared advantages: Both VR interaction types performed favorably in terms of flow experience, technology acceptance, preference, and satisfaction and evoked strong positive emotions. They share a common advantage of overcoming screen limitations and transforming into 3D spatial activities. Freeform creativity outperformed goal-directed training: Freeform creativity VR provided more pleasure and evoked stronger emotional responses than goal-directed training. It also demonstrated superior performance in terms of indicators such as flow experience, technology acceptance, preference, and satisfaction. Usability: Goal-directed training exhibited superior usability compared with freeform creativity, particularly in terms of overall response, clarity of information presentation, and learnability. This study contends that categorizing and optimizing complex tasks or leveraging intuitive operations to enhance VR usability is crucial in designing practical VR applications. Physical activity promotion: In this study, the goal-directed learning VR design failed to achieve activity effectiveness in physical stretching. This underscores the need for designers to incorporate more motivational elements, such as music, sound effects, and innovative virtual interactions into VR designs to evoke enjoyment, positive emotions, and immersion, thereby motivating users to continue using the system to achieve exercise goals. Although this study provided valuable insights, it has limitations that should be considered. Future research endeavors could explore the following avenues:  
Task segmentation and optimization: Both types of VR can facilitate diverse tasks. For example, freeform creativity can enable users to draw single lines using a brush or even create complex surfaces with both hands, whereas goal-directed training can engage users in a range of movements, from simple exercises to dynamic interactions like those seen in VR rhythm games featuring lightsaber interactions or boxing aerobics. Future studies could investigate the performance and efficiency differences across such diverse tasks. User Gender and Experience: Designing different VR tasks for males and females, as well as tasks of varying complexity for participants with and without VR experience, are important considerations. Future researchers are encouraged to study the differences in score distributions based on gender and experience, investigate the underlying reasons, and propose design recommendations accordingly. Sample Size and Diversity: This study's sample size of 33 participants did not cover all demographics and user backgrounds. We suggest that future researchers consider increasing the sample size and including more diverse participants in subsequent studies to enhance the generalizability of the results. User feedback and design trends: Future researchers could further investigate user feedback to optimize VR software. With ongoing advancements in VR technology, future studies can aim to improve usability and provide more learning resources and training content, thereby extending the results and contributions of this study. This research was funded by the National Science and Technology Council of Taiwan, grant number NTST 112-2410-H-239-010-MY2. The human research ethics committee of National Cheng Kung University approved this study on 7 October 2020 (REC number: NCKU HREC-E-109-223-2).