The effect that touching a projection augmented model has on object-presence

A projection augmented model (PA model) is a type of projection based haptic augmented reality display. It consists of a real physical model, onto which a computer image is projected to create a realistic looking object. Users can physically touch the surface of a PA model with their bare hands, which has clear experiential value for the types of applications for which they are being developed. However, the majority of PA models are front-projected and do not provide haptic feedback for material properties (e.g. temperature and physical texture), which suggests a user´s sense of object-presence will be reduced when this type of PA model is touched. (object-presence measures the subjective feeling that the object the PA model represents exists in a person´s environment, as opposed to a white physical model and a projected computer image.) Alternatively, if people consider PA models to be essentially computer generated objects (i. e. it is the projected image that gives the ´dummy´ physical model meaning), then the act of being able to touch computer generated information may increase object-presence. The empirical investigation reported in this paper found that object-presence was lower when this type of PA model was touched. The implications these results have for both PA models and other types of displays, are discussed.