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.