Tabletop setups are becoming increasingly popular. Although many researchers are developing different horizontal display setups, there are neither widely accepted standard input devices, nor preferred interaction techniques (such as touch-sensitive displays using fingers and styli).

The interaction with digital content, which is too far away, is a primary cause of problems with most of the current interaction metaphors. In most cases, participants have to go physically to the content before they can pick it up by touching the table surface. The authors of this paper propose the TractorBeam, a six degrees of freedom magnetic tracking device, which combines both pointing and touching the interface. The hybrid point-touch interaction technique allows users to point at distant targets and choose between point and touch for closer targets.

To evaluate the performance of the system, the authors conducted five very interesting user studies. First, they conducted a target selection study, in which they compared the speed and accuracy of selecting a target with the stylus and with pointing. Second, they conducted a target-docking study to compare the speed and accuracy of docking a target using the TractorBeam with a stylus-based touch interaction technique. In the first scenario, participants selected objects by pointing at them with the stylus. In the second setup, subjects made a selection by touching the stylus to the table’s surface. In the third study, the authors observed participants’ use of the TractorBeam interaction technique to determine which of the input strategies (point/touch/reach-and-point) users would choose to select different objects at different locations on the horizontal display. In the fourth study, the subjects had to assemble a 40-piece virtual jigsaw puzzle on the horizontal display using the TractorBeam and touch interface. In the fifth study, the authors observed the participants interacting with two sample applications (the jigsaw puzzle and solitaire) using a mouse and the TractorBeam. The studies showed that pointing was slower than touching for small, distant targets. In fact, distant objects were selected easier and faster by using the pointing method.

In summary, the evaluation gave really positive results for the hybrid point-touch interaction technique, and motivated the authors to do further tests on its usefulness in collaborative activities. This paper will help readers develop a good understanding of the importance of usability studies through its implementation of different interaction metaphors and devices for large display environments.