EVALUATION OF KEY SHAPES ON A TOUCHSCREEN SIMULATION OF A SPECIALIZEDKEYPAD

The effect of key shape on a touchscreen simulation of a flat touch-se nsitive keypad was investigated by rapid prototyping. A software proto type was developed of a hardware keypad that controlled chemical analy sis equipment. The prototype was used to answer some basic ergonomics questions concerning the design of the device keys. In a target select ion task, keys shaped as equilateral triangles were most precise, and least precise was a compound shape comprising of a rectangular lower p art and a triangular 'hat' as the upper part. No significant differenc es in the times taken to complete the task were found. It is suggested that the use of a touchscreen prototype is suitable when designing fl at-keypad layouts. Due to the visual nature of flat keypad use, where perception of the target must counter reduced tactile feedback, the de sign of shapes to aid the selection of keys is of paramount importance . It is concluded that rapid prototyping of hardware with graphical de signs and touchscreens is a powerful tool for the ergonomic design of interfaces. Copyright (C) 1996 Elsevier Science Ltd.