An empirical study on the smallest comfortable button/icon size on touch screen

Abstract

For the convenience of firefighters' decision-making and operation, touch screen display was chosen as the preferred interface for a fire information display system. Few studies were conducted to determine comfortable button/icon size on touch screens. This experiment investigated the effect of four factors on operators' performance with touch screen: 1) button size (20*20, 30*30, 40*40, and 50*50 pixels 2), spacing between buttons (0, 5, 10, and 20 pixels), 3) button/icon types (digit buttons only, picture icons only, combination), and 4) glove wearing (wearing vs. not wearing). 14 males were asked to accomplish a series of matching tasks on touch screen with the forefinger of right hand. Results showed that the spacing between buttons/icons, and wearing or not wearing a glove did not affect performance. Subjects pointed to the digit buttons faster than the other two kinds of buttons/icons. There was a significant difference among button/icon sizes. People performed best when it was equal to or bigger than 40*40 pixels. © Springer-Verlag Berlin Heidelberg 2007.