터치키의 위치 및 크기가 한 손 엄지손가락 누름 작업에 미치는 영향

Recently, mobile phones with touch keys replacing traditional keys have been developed and introduced to the market. Few studies, however, have been conducted on touch interface design for a mobile phone. This study investigated effects of touch key size and location on one-handed thumb input on a mobile phone. Three different touch key sizes (i.e. 4㎜, 7㎜, and 10㎜) and twenty five locations were examined in an experiment. A total of thirty subjects participated in the experiment in which they performed pressing touch keys on a mobile device. Two time-related measures (the first press time and task completion time) and two error-related measures (average number of errors, success rate at the first press) were collected. The results revealed that the touch key size of 7 and 10 ㎜ provided the best usability for time-related measures, while the touch key size of 10 ㎜ only for the other measures. In addition, two types of touch key locations (appropriate and inappropriate region) were statistically identified with respect to usability for every measure. The results of this study could be used to design touch keys that are able to enhance the usability of input tasks on mobile phones.