Creating hybrid user interfaces with a 2D multi-touch tabletop and a 3D see-through head-worn display

How can multiple different display and interaction devices be used together to create an effective augmented reality environment? We explore the design of several prototype hybrid user interfaces that combine a 2D multi-touch tabletop display with a 3D head-tracked video-see-through display. We describe a simple modeling application and an urban visualization tool in which the information presented on the head-worn display supplements the information displayed on the tabletop, using a variety of approaches to track the head-worn display relative to the tabletop. In all cases, our goal is to allow users who can see only the tabletop to interact effectively with users wearing head-worn displays.