Understanding finger postures when touching targets on the touchscreen of mobile devices1

This paper presents the results of a preliminary study on the interaction of the fingertip and a mobile device’s touch screen. The objective of this study is to identify the finger postures that will be included in the main study on the contact area in the interaction between fingertip and a flat surface. Twenty participants (15 males and 5 females) took part in this study. They were asked to complete two tasks in a sitting posture. In the first task, they had to touch targets on the mobile device screens by tapping them sequentially, while in the second task they were asked to connect the targets with straight lines. The results showed that the participants used mainly their thumbs and index fingers to touch targets on the screen of the devices. Only a small number of participants used their middle finger, and only in a few touching activities.