TouchGrid: Touchpad pointing by recursively mapping taps to smaller display regions

Abstract

Touchpad devices are widely used but lacking in pointing efficiency. The TouchGrid, an instance of what we term cell cursors, replaces moving the cursor through dragging the finger on a touchpad with tapping in different regions of the touchpad. The touchpad regions are recursively mapped to smaller display regions and thereby enable high-precision pointing without requiring high tapping precision. In an experiment, six subjects used the TouchGrid and a standard touchpad across different numbers of targets, distances to targets and target widths. Whereas standard touchpad operation follows Fitts' law, target selection time with the TouchGrid is a linear function of the required number of taps. The TouchGrid was significantly faster for small targets and for tasks requiring one tap, and marginally faster for two-tap tasks. Error rates tended to be higher with the TouchGrid than the standard touchpad. All subjects preferred the TouchGrid.

Acknowledgements

The IT University of Copenhagen supported Morten Hertzum, in part. Niels Ebbe Jacobsen provided valuable comments on a draft version of the manuscript. Special thanks are due to the people who participated in the experiment as subjects.