Effects of Aging on Small Target Selection with Touch Input

Age-related declines in physical and cognitive function can result in target selection difficulties that hinder device operation. Previous studies have detailed the different types of target selection errors encountered, as well as how they vary with age and with input device for mouse and pen interaction. We extend this work to describe the types of age-related selection errors encountered with small touchscreen devices. Consistent with prior results, we found that older adults had longer target selection times, generated higher error rates, and encountered a broader range of selection difficulties (e.g., miss errors and slip errors) relative to a younger comparison group. However, in contrast to the patterns previously found with pen interaction, we found that miss error (i.e., both landing and lifting outside the target bounds) was a more common source of errors for older adults than slip error (i.e., landing on the target but slipping outside the target bounds before lifting). Moreover, aging influenced both miss and slip errors in our study of touch interaction, whereas for pen interaction, age has been found to influence only slip errors. These differences highlight the need to consider pen and touch interaction separately despite both being forms of direct input. Based on our findings, we discuss possible approaches for improving the accessibility of touch interaction for older adults.