User Interface (UI) Design and User Experience Questionnaire (UEQ) Evaluation of a To-Do List Mobile Application to Support Day-To-Day Life of Older Adults.

Because of the spread of smartphones, older adults enjoy the assistance of smartphones. However, fewer mobile applications are designed for older adults. Smartphone user interface (UI) serves as an external brain to capture information, and older adults may have memory complaints that affect self-confidence and lead to memory decline. Non-declarative memory requires more effort. Therefore, this study aims to design and evaluate a to-do list application to help older adults encode, store, and retrieve non-declarative memory, such as tasks they plan to do. We recruited 15 participants (5 men and 10 women) aged 60 to 75 years old (SD = 5.32). They were asked to complete nine usability tasks, and to answer a user experience questionnaire (UEQ) and a few interview questions. Sixty percent of users completed with only one or two attempts (median = 2.80, SD = 1.63). We found three usability issues and proposed an iteration plan. The application has attractiveness, efficiency, dependability, stimulation, novelty, and good perspicuity for older adults. The product was rated excellent except for perspicuity, which met the users' expectations. This indicates that the user is satisfied with the application prototype. The results of this measurement can be utilized as a benchmark for the next model for developing mobile to-do list applications on user experience.