In Augmented Reality there is an intimate relationship between virtual
and physical objects. The physical objects can be enhanced in ways not
normally possible such as by providing dynamic information overlay,
private and public data display, context sensitive visual appearance, and
physically based interactions. AR applications based on a tangible
interface metaphor use physical objects to manipulate virtual information
in an intuitive manner. In this way people with no computer background
can still have a rich interactive experience. For example, in the Shared
Space interface users could manipulate three-dimensional virtual objects
simply by moving real cards that the virtual models appeared attached to
[Poupyrev 2000]. There was no mouse or keyboard in sight. This property
enables even very young children to have a rich educational experience.