Devices for On-the-move Applications
Ying K. Leung, Chris Pilgrim and Kon Mouzakis, The Advanced Technologies Group, School of Information Technology, Swinburne University of Technology, P.O. Box 218, Victoria 3122, Australia
The popularity of mobile computing devices is mainly attributed to two important features: portability and connectivity. These features bring about many new applications, enabling the user to perform useful work on the move. Pen-based devices in particular are gaining wide acceptance because of their natural physical interface and the ability for the user to input data without a keyboard.
Despite the diverse application domain of pen-based devices, there are only a limited number of selection strategies available for user interaction ( Ren and Moriya, 1997). The use of the pe, (or the pointing device) to select an item on a menu or a check box is the most common action taken by the user with these mobile devices. The scarcity of screen space of mobile devices is invariably one of the most constraining factors confronting the interface designer, as the designer often has to compromise between visibility of interface controls and the number of controls that can be displayed. For applications involving the user interacting with the device on-the-move, the lack of screen space places another level of complexity in the user interface design as pointing accuracy invariably diminishes.
Whilst Fitts' law ( Fitts 1954) provides a useful basis for estimating user performance in pointing tasks, more specific design guidelines are needed to deal with situations involving the user on the move. Given the inherent