Fig. 1

The reality-virtuality continuum. AR—augmented reality; AV—augmented virtuality; VR—virtual reality [based on (Milgram et al. 1995)]. In a highly influential paper, Milgram, Takemura, Utsumi, and Kishino (1995) proposed the reality-virtuality continuum to classify Virtual, Augmented, and Mixed reality technologies. On one side of the spectrum is the real world (reality) and, on the other side of the spectrum, the fully virtual world (virtuality) where Virtual Reality (VR) in its strict sense resides. In between the extremes, stands Augmented Reality (AR)—which relies mostly on real world elements but with the addition of virtual entities; the best known (and controversial) example of AR has been Pokemon Go! (Serino et al. 2016; Zsila et al. 2018)—and Augmented Virtuality (AV) with the opposite of AR, that is, mostly virtual world but with the addition of ‘real’ entities. AR and AV are cases of Mixed Reality (MR), where real and virtual elements are intertwined within the application. For the purpose of this paper and for simplicity, we refer to AR, AV, and VR all as virtual and mixed reality (VMR) applications because they all have some degree of virtual components introduced into the application