The effects of redundancy in user-interface design on older users

This paper presents an experiment designed to investigate if redundancy in an interface has any advantage over either words-based or symbols-based interfaces for older people during early or intermittent encounters with a device. Although older people used all three interfaces more slowly and less intuitively than younger ones, interestingly there were no age differences in terms of errors made on the words-based interface. In terms of differences between interfaces, older people (65+) completed tasks on the words-based interface faster and more intuitively than on the redundant (words and symbols) interface. Younger participants completed tasks faster on the redundant interface. Overall, this research suggests that a simple words-based interface is most effective for older users and that recommendations to use redundant interfaces for greater usability for older people may need to be re-visited.