How to improve the quality of human performance with natural user interfaces as a case study for augmented reality

The embodiment of computers in the work place has had a tremendous impact on the field of human-computer interaction. Graphic displays are everywhere, the desktop workstations define the frontier between the computer world and the real world. Users spend a lot of time and energy to transfer information between those two worlds. This could be reduced by better integrating the virtual world of the computer with the real world of the user. The most promising approach to this integration is Augmented Reality (AR). The expected success of this approach lies in its ability to build on fundamental human skills: namely, to interact with real world objects! To compare the advantages and disadvantages of a "Graspable User Interface" a field study was carried out. We investigated the effects of four different interaction techniques (command language interface, mouse interface, touch screen interface, and a DigitalDesk) with two different methods: (a) an inquiry with a questionnaire, and (b) a field test for public and anonymous use. (a) Results of the inquiry: 304 visitors rated the usability of all four stations on a bipolar scale. The touch screen station was rated as the easiest to use interaction technique, followed by the mouse and DigitalDesk interface; the "tail-light" was the command language interface. (b) Results of the field test: The analysis of 9'006 automatically recorded contacts to one of the four stations shows that the highest chance to win the game could be observed for the DigitalDesk interface technique. We conclude that the DigitalDesk as a representative example for AR is a promising candidate for the next user interface generation.