Performance study on touch-pens size in three screen tasks

Experiments were aimed at investigating the performance of various sizes of touch-pens. The touch-pens were of three different lengths (80, 110 and 140 mm) and four different diameters (5.5, 8, 11 and 15 mm). Three screen tasks were used for determining a reference of ideal dimensions of a pen-based product. Sixteen subjects used 12 touch-pens to perform pointing-and-clicking, writing and drawing tasks. The subjects were asked to rank their preference after each task in the test. The results showed that the length of touch-pens should be designed to extend beyond the handbreadth when gripped. A touch-pen that facilitates natural pointing-and-clicking, writing and drawing tasks each requires a suitable diameter size. However, these tasks are typically performed together, in particular, the pointing-and-clicking and writing tasks. The recommended diameter for all three combined tasks is 8 mm. This finding indicates that selecting a touch-pen with a diameter of 8 mm and a length of 100 mm or longer is suitable for all pen-based devices.