Optimal Slope of Touch Panel －Comparison between Young and Older Adults－

Touch panels are becoming increasingly common alternatives to traditional indirect devices such as mouse. However, older adults are not willing to utilize touch-panel based ATM or ticket machines, because they feel that using ATM properly is too difficult and annoying for them. The aim of this study was to identify an optimal slope of touch panel interface. Whether using a direct input device by older adults would lead to smaller difference of performance between preferred and non-preferred hands was also examined. For both young and older adults, the slope conditions of 30, 45, and 60 degrees, and the target size of 60 x 60 pixels were found to lead to higher performance. With the increase of movement distance d, the movement velocity tended to increase for both age groups. The difference of movement velocity between young and older adults tended to increase with the increase of movement distance d. The difference of performance between nonpreferred and preferred hands was smaller relative to their young counterparts. Moreover, the difference of performance between young and older adults was smaller when using a touch panel than when using a mouse.