## 4 Discussion
### Lessons Learned from the Design and Evaluation of Each Application Case Study  
Further research is needed into user-centered design and HCI methods tailored for XR environments, as well as exploration of innovative ways to authenticate and monetize digital cultural heritage using emerging technologies. These are critical for advancing the potential of Web3 metaverse applications in CH and tourism innovation contexts. The review of the Chilly Mo application use case focused on showing how the overall process of UX Design Thinking is used during the early stages of the development process. It showcased the use of a moodboard, a storyboard, persona descriptions, early stage task  
Figure 15: Eight-stage framework for physgital cultural heritage XR app development. diagram visualization, early stage Hierarchical Task Analysis, early stage prototyping using hand-drawn sketches, using computer generated templates with wire-frame UXUI task-flow drawings, mock-ups of the smartphone screen-views of the VR experience, interviews to get early targeted qualitative user feedback, and online surveys to get early quantitative and qualitative feedback on the prototype. It specifically aimed to illustrate the use of persona descriptions to identify representative users, and the respective user needs for typical users, as well as atypical users, early on in the development process. The Chilly Mo study meticulously applied the five stages of Design Thinking (empathize, define, ideate, prototype, and test) and the evaluation methods to validate the prototype's usability and how these were implemented. The Cham Culture AR case focused on developing a minimum viable prototype to test converting stone reliefs into AR-based educational games. To assess user perception, the widely used SUS questionnaire was applied to measure desirability. The total SUS score is a popular measure, because it provides one data-point about perceived usefulness, for easy comprehension by all stakeholders involved in the decision-making about investing and managing development projects. For example, [PERSON] et al. (2022) [133] utilized Design Thinking to create a gamified mobile AR application for cultural tourism, and used the SUS, with an excellent score of 88.5. Similarly, [PERSON] et al. (2023) [134] employed Design Thinking to develop AR/VR applications for preserving Bali's Lontar Prasi, resulting in an average SUS score of 80, indicating excellent user satisfaction and highlighting the effectiveness of iterative design improvements based on user feedback. The user feedback they collected allowed them to make improvements by making changes to icon display, 3D character information, and UI positioning. The Cham Culture AR use case review also discussed the paucity of AR evaluation methods and showcased the application of Universal Design principles' heuristic evaluation method that was specifically developed for early AR app testing to address the gap in suitable methods. [PERSON] et al. (2008) [135] and [PERSON] (2017) [136] address the long-standing gap in evaluation techniques for AR by reviewing or developing instruments to measure user experiences and immersion. However, neither explicitly covers QR code-based AR mobile phone apps, simply because such technologies were not commonly in use at the time these studies were conducted. This omission can limit the applicability of their methods to newer AR or XR cultural heritage applications, which often rely on mobile-based QR markers or object recognition for location-based interactions. Moreover, while these studies offer significant foundational insights, they do not fully explore the unique challenges of designing for rich cultural heritage contexts--such as integrating multisensory feedback, collaborating in shared AR spaces, or addressing long-duration user engagement. Consequently, evolving AR platforms and domain-specific needs continue to call for more flexible, standardized, and context-aware evaluation frameworks.