Immersion

Immersion is a feature of virtual reality, and it is an unique experience that is connected with the world of VR. Astheimer et al. (1994) define immersion as the feeling of a VR user, that his virtual environment is real.

In a 2004 work titled Postmodernism and the Three Types of Immersion, Adams presents three main categories of immersion: tactical, strategic, and narrative. Tactical immersion gives the users the experience that they are accurately performing actions in the virtual world with convincing feedback. Strategic immersion which is associated with mental challenge; narrative immersion occurs when users become invested in a story, and is similar to what is experienced while reading a book or watching a movie.

Björk and Holopainen, in their book Patterns in Game Design (2004), divide immersion into three similar categories, but they call them: sensory-motoric immersion, cognitive immersion, and emotional immersion, respectively. In addition, they also add a new category named spatial immersion. It occurs when a user (for example a player in a video game) feels the simulated world is perceptually convincing (Björk & Holopainen, 2004).

Interactive Hardware Components

VR systems involve interface hardware components (Brooks, 1999; Burdea & Coiffet, 2003; Magnenat-Thalmann & Thalmann, 1999; Riva, 2006). They consist of:

• The input devices which report, in real time, the position and the movements of the users in the virtual worlds. They permit the human participants to give electrical signals to the computer which can be transformed as specific commands. Input devices can comprise gloves, trackers, keyboards, and mouse (2D or 3D);

• The output devices (visual, aural, and haptic) give the users the illusion to be immersed in the virtual environments. For example, the visual display, which is an output tool, is a kind of helmet that places a television-like screen over each eye, blocking one’s view of the physical world. Instead, of the physical world, one sees a 3D rendition of a place created by computer graphics workstation.

• The graphic rendering system generates the virtual scenarios and the virtual environments; and

• The database construction and virtual object modeling software realize virtual scenarios and detailed and realistic models of the virtual world. In particular, the software handles the geometry, texture, intelligent behavior, and physical modelling of any object included in the virtual world.

Figure 1 shows the components of virtual reality. In Figure 2 are shown head-mounted display (HMD) and motion-sensing data gloves.

Figure 1. VR’s components

Figure 2. Head mounted display and data gloves (Credits: NASA. Source: Immersion (virtual reality), 2015

Vr: Other Classification

Another classification of VR is the method of display. VR can be displayed as immersive and non-immersive. Immersive VR involves a high degree of interactivity and high cost peripheral devices, for example the head mounted displays. Non-immersive VR is often called desktop VR and it is in the form of a window into a virtual world displayed on a computer’s monitor (Earnshaw, Chilton, & Palmer, 1997). In particular, low-cost non-immersive VR is a solution used in the educational field.

Riva (2006) classifies virtual reality in 5 categories (desktop VR, fully immersive VR, CAVE, telepresence, augmented reality). Table 1 resumes this classification and its features.

Table 1. Virtual reality classification

Type	Features
Desktop VR	It is a low cost solution for virtual reality, which uses a computer monitor as a display to provide graphical interface for users. The interaction with the virtual world is not high, and it can be made via mouse or joystick, and it does not require any expensive hardware or software, and it is also relatively easy to develop.
Fully Immersive VR	This is the name given to a virtual environment in which the user has the illusion to be fully immersed within it. This illusion is created using immersive output devices (for example, stereoscopic goggles) and a system of tracking to have the correct correspondence between user’s movements and the feedback in the virtual environment.
CAVE (Cave Automatic Virtual Environment)	It is a room where its walls are typically made up of projection screens, where a computer generated world is projected on the walls. Its name is also a reference to the allegory of the Cave in Plato's Republic in which a philosopher contemplates perception, reality, and illusion. This solution is particularly suggested for collective VR experience because different people can share the same experiences at the same time.
Telepresence	This term is used to describe a set of technologies, such as high definition video, audio, and other interactive elements, that permit the users to feel or appear as if they are present in a location in which they are physically not located. Users can influence and operate in a world that is real but in a different location. This technology is used as a collaborative tool. Telepresence and videoconferencing are different. Telepresence offers face-to-face interactions between the people in the meeting through the transmission of life-size, high-definition images and audio.
Augmented Reality (AR)	It is a direct or indirect view of a real-world environment which elements are augmented (or supplemented) by computer-generated sensory input such as graphics, sound, and video. For example, the user’s view of the world is enriched by virtual objects, usually to provide information about the real environment. Augmentation is in real-time. Typical hardware components for augmented reality are: processor, input devices, display, sensors, and smartphone.

Benford, Greenhalgh, Reynard, Brown, and Koleva (1998) classify augmented reality as separate from both VR and telepresence (see Figure 3).

Figure 3. Classification of shared spaces according to transportation and artificiality (Benford, Greenhalgh, Reynard, Brown, & Koleva, 1998)

Mixed Reality

In 1994, Paul Milgram and Fumio Kishino introduced Mixed Reality (MR), sometimes referred to as hybrid reality. They also introduce the “virtuality continuum” which extends itself from the completely real to the completely virtual environment passing through augmented reality and augmented virtuality ranges.

Figure 4. shows the reality-virtuality continuum by Milgram and Kishino (1994), where augmented reality is one part of the general area of mixed reality (van Krevelen & Poelman, 2010). In particular, they affirm that virtual environments, VR can replace the surrounding environment by a virtual one.

Figure 4. Reality-virtuality continuum (Milgram & Kishino, 1994)

Milgram, Takemura, Utsumi and Kishino (1994) introduced a three-dimensional taxonomic framework for classifying Mixed Reality displays, comprising: Extent of World Knowledge (EWK), Reproduction Fidelity (RF) and Extent of Presence Metaphor (EPM) (see Figure 5).

Figure 5. Three dimensional taxonomic framework for classifying MR displays (Milgram, Takemura, Utsumi, & Kishino, 1994, p. 291)

HISTORY OF VIRTUAL REALITY USE IN EDUCATION

Several studies confirmed the potential of VR in education and in different disciplines, and its potential in education is recognized and supported by interesting results (Byrne, 1996; Chung, Huang, Yeh, Chiang, & Tseng, 2014; Connolly, 2008; Gerval et al., 2002; Gerval, Popovici, & Tisseau, 2003; Häfner, Häfner, & Ovtcharova, 2013; Le, Pedro, & Park, 2014; Matsuda, Nakayama, & Tamada, 2015; Merchant, Goetz, Cifuentes, Keeney-Kennicutt, & Davis, 2014; Pantelidis, 2010; Popovici et al., 2009; Sala & Sala, 2005; Sala, 2013a; Stangel & Pantelidis, 1997; Traub, 1991; van Krevelen & Poelman, 2010; Winn, 1993; Youngblut, 1998).

Winn affirmed the reasons for using VR in education. In particular, immersive VR furnishes a non-symbolic experience which helps students in their learning path (Winn, 1993).

Hedberg and Alexander, in 1994, furnished a list of questions that they felt should be asked when contemplating the use of VR in education. They selected 12 questions which are:

1. 1. To what extent is collaboration with peers possible and useful in the VR experience?

2. 2. What use does the learner make of conversations, stories and multiple points of view?

3. 3. What and how does the learner learn in a 'virtual' community of practice?

4. 4. Is there a complex combination of physical and cognitive skills?

5. 5. Are the motivation and the context important?

6. 6. Does the learner need to combine information from different forms of representation (aural, visual, temporal, etc.) and is a context required to limit the cognitive load of the task?

7. 7. Does the learner need to experiment with a scenario which might have dangerous consequences if actually experienced?

8. 8. Does the learned concept require links to objects which behave with a defined set of attributes and relationships?

9. 9. Are the learner's explorations: independent of size of the world being explored (microscopic or macroscopic)?

10. 10. Of physical and improbable phenomena, related to the creation of micro worlds, independent of time explorations with beings real, or historical, within their context)?

11. 11. Is the learned concept a relationship in space independent of physical laws?

12. 12. Does the learner have to work with abstract relationships, manipulate data structures and mathematical functions?

In 1996, Christine Byrne explored VR as an educational tool. She based her doctoral work on testing students' assembling of a virtual molecule of water, using an immersive virtual environment with haptic input. The virtual chemistry world encouraged students to learn by exploring and interacting with the information. The immersive virtual world was created by high school students. Instead of sitting in a classroom and passively viewing images of atomic orbital, students placed electrons into an atom see the atomic orbital appear as the electron buzzes. Her research results were interesting. Byrne claimed that interactivity was found to be significant, but immersion was found to be insignificant. She suggested that issues of training, world design, assessment, hardware resolution, and student population as possible reasons for immersion’s lack of significance in her study (Byrne, 1996). She also affirmed that the results of her study have not shown VR to be superior to other methods of instruction; but interactivity, a VR’s feature, could be important.

Another interesting survey of research was done by Christine Youngblut during the 1990’s. In her 1998 study, she said that VR can be applied in different kind of school (from elementary schools to colleges). This technology introduces important aspects of constructivist learning. The role of the teacher changed to facilitator that helps students in their learning paths, building ideas. Students enjoy using pre-developed applications and developing their own virtual worlds (Youngblut, 1998).

These studies emphasized that VR does not furnish only passive copy of reality, but its reconstruction is a model where users can act. It reacts and behaves as in real environment. This important feature overcomes the inherent limitations of perception, which should be applicable only to objects physically perceptible. As technology continues to improve, VR systems will become pervasive instrumentation for research in education across the disciplines.