3DKey: An Accordion-Folding Based Virtual Keyboard for Small Screen

Nowadays, handheld devices are more and more equipped with functionalities and applications so that they almost serve like a desktop computer. However users find them tedious and tiring to input text due the tiny keys of their virtual keyboard. In this paper, we discuss a new text entry method (3DKey) based on addition of a third dimension to traditional virtual keyboard to overcome the small screen constraint of handheld devices. In this context, the accordion-folding the virtual keyboard is used as a solution to expand keys leading to easier selection. Thus our 3DKey virtual keyboard can be seen as composed of two zones: an accordion-folded zone and a spread zone. Our study showed that users achieved more accurate and relatively faster text entry with 120° accordion-folding and predictive spreading virtual keyboard, which resulted in speed improvement of 37.71 %, than with traditional virtual keyboard.