## 4 Discussion
### Lessons Learned from the Design and Evaluation of Each Application Case Study
This use case study showcased how to use triangulation of HCI methods as a minimum development methodology, to achieve rapid prototyping and user feedback regarding desirability and effectiveness for teaching and learning. Triangulating design and evaluation methods is key to rapidly producing a viable prototype. By combining persona descriptions, heuristic evaluation, and the SUS, teams establish a swift, minimum quality control pipeline. Persona descriptions anchor design choices in authentic user needs, ensuring that early ideas resonate with real motivations and contexts. Heuristic evaluation then provides a quick, expert-driven scan for major usability flaws, allowing fixes before costly user testing. The SUS questionnaire captures user perceptions of ease-of-use through a concise, standardized format. This synergy of qualitative and quantitative feedback guarantees that each design iteration meets a threshold of functionality and usability. This is vital when time or budget are scarce. As a result, the team can present a lean yet reliable MVP to investors, demonstrating genuine market potential and readiness. It also mitigates risk by preventing deployment of an untested or subpar product. Ultimately, triangulation offers a practical safeguard: persona insights, heuristic checks, and objective usability scores give development teams confidence in their proof-of-concept, all while operating under tight deadlines. The Memories of Kellie application illustrated the process of HCI-informed research and development, which starts with a thorough literature review to identify any user needs and any potentially useful design solutions other UX developers identified, rather than diving straight into coding. By examining existing knowledge on digital storytelling and cultural heritage, the team can identify foundational design principles, covering functionality, emotional impact, and user needs, to inform their design decisions, before any prototype is built. This ensures that, when development begins, the resulting application aligns with real-world user needs, rather than being based on guesswork. The Memories of Kellie application exemplifies the design and evaluation methods of human-centered interaction design and evaluation: literature research to inform the design choices, hypothesis development about best design ideas, prototype building according to the literature-informed design ideas, testing of the prototype with representative end-users to assess whether the design ideas work as predicted from the literature research, and writing advice on redesign options derived from the user testing. It demonstrates why creating a tangible model is essential: it allows the researcher to test how the theoretical insights from the literature review translate into practical design solutions. This allows the developers to test their theory that the desired emotional and information goals are met by the design choices of incorporating interactive panels, soundscapes, and visual feedback. The Fort Ontario use case review focused on the use of combining qualitative and quantitative evaluation methods. For qualitative evaluation, the cognitive walkthrough (CW) was used, which is a step-by-step technique used to spot where new users might struggle when trying out an interface or application. In this project, the student applied it on-site at Fort Ontario, by asking participants to guide themselves through the self-directed AR tour. Each step--such as launching the app, following on screen prompts, and interacting with AR elements--was reviewed for potential confusion or friction. This method generates quick, low-cost feedback since it pinpoints issues as participants walk through the tasks, rather than requiring complex setups or lengthy observation sessions. Traditionally, this method is used by HCI researchers, as it was developed to be used early in the design journey when the application is not sufficiently robust and ready to be evaluated with end-users.