Abstract
With the accelerated technology innovation as well as increasing aging population, the discussion about older users’ technology adaptation has become more and more extensive. Among all of the difficulties, navigation problem on mobile phones hinders older users from adapting quickly and easily. Due to the elderly’s physical limitation and lack of mobile phone-related knowledge, their navigation performances are usually worse than younger users’. In this research, navigation difficulty was explained with the viewpoint of mental model, and solved with the concept of coherence model and psychological scaling. There were four stages in the research. First of all, 30 older users were invited to a functional requirement investigation. The result shows that the elderly view the mobile phone as a device for elevating sense of safety. They also need functions assisting both physical and cognitive degeneration. Then, 13 older people (without mobile phone using experience) were invited to conduct the functional card sorting. The result of card sorting was analyzed with hierarchical clustering. After sorting the card, participants were also required to provide their sorting criteria, and the criteria were summarized with affinity diagram to become the name of the submenu. The output dendrogram of hierarchical clustering shows that the mobile phone functions are devided into two clusters. They are functions with which the participants have not exposured and functions related to telephone use. These two clusters were named as advanced functions and phone-related functions respectively. Finally, 16 older participants’ task completed rate, operation time and additional steps were measured on the original menu and the menu design based on coherence model. The result is that the menu design based on coherence model can make participants’ menu structure predicton more correct, but it has no influence on reducing the operation time.