Virtual Reality, Augmented Reality, and Mixed Reality in Education: A Brief Overview

Virtual Reality

In the 19^th century, formal education was based on lectures and recitations. The Swiss pedagogues Johann Heinrich Pestalozzi (1746-1827) was one of the first that studied what is commonly known as “hands-on learning”. He observed that students learn best through physical activity and if they use their senses (Pestalozzi, 1803). Nowadays, modern educational environments find in the new technologies a way to improve the learning paths. For example, VR, AR, and MR can stimulate the senses of the students, involving them in learning activities.

In 1987, Yaakov Garb used the term “virtual reality” as title of a paper. VR is the capability to represent the world with visual symbols (Garb, 1987). Garb’s point of view is far from computer technology. While Garb used the term ‘virtual reality’ as the title of a paper on 1987, the term was used to represent the world with visual symbols. It was two years later when Lanier used the term specific to the world of computer technology (Lanier, 1989). He referred the term to the world of computers: VR exists only as an electronic image, without any connection with the real world. As Krueger (1991) stated, “The term therefore typically refers to three-dimensional (3D) realities implemented with stereo viewing goggles and reality gloves” (p. xiii). VR is a technology which involves information technology, computer graphics and electronics, and it gives its users the illusion of being immersed in a computer-generated virtual world with the ability to interact with it. VR has also been defined as an experience in which the users are immersed in a responsive virtual world. This implies users’ dynamic control of viewpoints. (Brooks, 1999).

Burdea and Coiffet (2003) describe VR as a simulation in which computer graphics are used to create a realistic-looking world. The synthetic world is dynamic, responding to the user's input (gesture, verbal command, etc.). This introduces the real-time interactivity, which is a key feature of this technology, but computer science evolution requires a new definition of VR. More recently, the Encyclopædia Britannica (2019) describes VR as a technology that permits the use of modeling and computer simulation, where a person can interact with a sensory environment or with an artificial three-dimensional visual environment.

In 1997, Rosenblum & Cross define the three primary requirements of a VR system. They are:

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  Immersion refers to a realistic feeling that allows users to have exposure to a virtual environment. The perception is created surrounding the user by the VR technologies and by its devices (e.g., data gloves, head mounted display, sound or other sensorial stimuli), that provide an engrossing total environment (Wu et al., 2015). Immersion requires physically involving the user, both by capturing exclusive visual attention and by transparently responding to 3D input, through use of devices such as a head-tracker, 3D mouse, wand, data glove, or fully instrumented body suit;

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  Interaction is a kind of action that occurs as two or more objects have an effect upon one another. In VR what is realized through the 3D control devices to investigate and control the virtual environment; and

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  Visual realism provides an accurate representation of the virtual world using computer graphics tools.

Immersion is a feature of VR and MR. characterized by different degrees of user involvement.

It is a unique experience that is connected with the real world and the virtuality. Astheimer et al. (1994) define immersion as the feeling of a user, that his virtual environment is real. In a 2004 paper titled Postmodernism and the Three Types of Immersion, Adams presented 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 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 (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 that occurs when a user feels the simulated world is perceptually convincing (Björk & Holopainen, 2004).

Interaction refers to the natural interaction between the users and the virtual scenes. VR, AR, and MR systems involve interface hardware components. For VR they consist of:

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

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  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.

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

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  The database construction and virtual object modelling 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.

Visual realism refers on the ability of VR to create an immersive 3D spatial experience when the user perceives that is to a virtual world (for example, being a player in a videogame). This is affected by the perceived feeling of artificiality and transportation (Benford et al., 1998). To be credible, this perception requires different interactions which should be in real-time (Riva, 2006). For example, the user requires instant feedback of his movements, position, and sensations (Martín-Gutiérrez et al., 2017).

More recently, visual realism was defined as the extent to which an image appears to people as a photo rather than generated by computer (Fan et al., 2017).