Most current multi-touch devices use direct input, especially larger surfaces. In this context, we asked how much the advantages of multi-touch depend on the directness of input. An indirect multi-touch device has several potential advantages, such as interaction from a distance (remote control), different control-display ratios (allowing for larger screens), more ergonomic settings (looking straight while resting hands), etc. We designed a study to explore some aspects of indirect multi-touch input for large surfaces, comparing it to direct input. The test subject were asked to perform bimanual tasks consisting of pointing and dragging actions.
While there is a performance penalty, users understood the indirect interaction instantly and were able to complete all tasks. Our results suggest that the main decrease in performance is due to the difficulty of estimating the distance between hands and surface while looking at the screen. Techniques which allow users to rest their hands on the surface could potentially overcome some of these difficulties we observed.