Evaluating tactile feedback and direct vs. indirect stylus input in pointing and crossing selection tasks

We present a pair of experiments that explore the effects of tactile-feedback and direct vs. indirect pen input on pointing and crossing selection tasks. While previous work has demonstrated the validity of crossing as a useful selection mechanism for pen-based computing, those experiments were conducted using an indirect input device -- one in which the pen-input and display were separated. We investigate users' performance with pointing and crossing interfaces controlled via not only an indirect input device, but also a direct input device -- one in which the pen-input and display are co-located. Results show that direct input significantly outperforms indirect input for crossing selection, but the two modalities are essentially equivalent in pointing selection. A small amount of tactile feedback is shown to be beneficial for both pointing and crossing selection, most noticeably in crossing tasks when using direct input where visual feedback is often occluded by a hand or stylus.