Designing Interfaces for Older Users: Effects of Icon Detail and Semantic Distance

Older users are increasingly using digital means (especially the Internet and mobile devices) for work and leisure. Yet, until recently, researchers have not paid sufficient attention to how one can adapt the human-computer interface to older users. In this paper, we propose an approach to adapting interfaces to older users that is based on the knowledge of design and knowledge of age-related capabilities and needs. We concentrate on icons, which are perhaps the most common means of controlling human-computer interaction. First, we determined age-related cognitive impairments that might affect icon identification and selected two icon attributes that we could adapt to overcome performance degradation. We then conducted an experiment to test the hypothesized differences between young and old adults in terms of the impact of icon design on user performance. The two attributes of icon design were level of detail in the icon (i.e., the number of elements that constitute the icon) and its semantic distance (i.e., the distance between the meaning of the icon and function it represents). We found that both attributes affected the performance of older users more strongly than they did young users except for an extreme case in which the negative impact on young users when adapting for older users was devastating. We believe that these results demonstrate that adaptation of icons for older users is desirable and feasible but must be done with caution. We need more research to determine the nuances and limitations of adaptation to understand the adaptation of other design attributes by going beyond the cognitive aspects to the physical, affective, and social aspects of human computer interaction