*NOTE* This article is an excerpt. The complete text is available on-line at the URL noted at the end of the article.
This material is made available under license from CANCOPY for personal use only by students enrolled in EDPY488 and EDIT 571 during the Spring Session, 2001, at the University of Alberta. Any alteration to the content or further distribution in any form is strictly prohibited.
IMMERSIVE TUTORING SYSTEMS:
VIRTUAL REALITY AND EDUCATION
AND TRAINING
Joseph Psotka, Ph.D.
U. S. Army Research Institute
ATTN.: PERI-IIC
5001 Eisenhower Avenue
Alexandria, VA 22333-5600
(703)274-5540/0892
Psotka@alexandria-emh2.army.mil or psotka@l98.97.199.1
FAX: 274-5461
Abstract
In the half dozen years since a previous thorough overview of intelligent tutoring and computer based instruction ( Nickerson and Zodhiates, 1988) the change of technologies has been breathtaking. Although we knew back then that what we were doing on expensive Lisp machines would soon be possible on ordinary personal computers, it is still unnerving to see not only that it is now possible, but that so much more is possible. l~he virtual reality (VR) technologies that ha= ve transformed the landscape in the intervening years (e.g. Rheingold, 1991) offer unique new viewpoints on the core goals of training and education. What distinguishes VR from all preceding technology is t he sense of immediacy and control created by immersion: the feeling of ~being there~ or presence that comes from a changing visual display dependent on head and eye movements. This paper will provide an introduction to the technology of VR and its possibilities for education and training. It will focus on immersion as the key added value of VR, and begin to analyze what cognitive variables are connected to immersion, how it is generated in synthetic environments, what immersion is, and what its benefits are. It is clear that a principled program of research is needed to uncover the instructional conditions that VR is best suited for, over other available media and technologies, if this new technology is to be used wisely and effectively. The central research question is the value of tracked, immersive visual displays over non-immersive simulations. The paper will provide a brief overview of existing VR research on training and transfer, education, and procedural, cognitive and maintenance training. It will close with an examination of important future issues: augmented reality, networked VR, edutainment, authoring systems, and equity
Voice Synthesis and Recognition
The Psychological Experience of Immersion
In the half dozen years since a previous thorough overview of intelligent tutoring and computer based instruction ( Nickerson and Zodhiates, 1988) the change of technologies has been breathtaking. Although we knew back then that what we were doing on expensive Lisp machines would soon be possible on ordinary personal computers, it is still unnerving to see not only that it is now possible, but that so much more is possible. The virh~al reality (VR) technologies that ha ve transformed the landscape in the intervening years (e.g. Rheingold, 1991) offer unique new viewpoints on the core goals of training and education. What distinguishes VR from all preceding technology is t he sense of immediacy and control created by immersion: ~e feeling of "being there" or presence that comes from a changing visual display dependent on head and eye movements. This paper will provide an introduction to the technology of VR and its possibilities for education and training. It will focus on immersion as the key added value of VR, and begin to analyze what cognitive variables are connected to immersion, how it is generated in synthetic environments, what immersion is, and wl~at its benefits are. It is clear that a principled program of research is needed to uncover the instructional conditians that VR is hest suited for, over other available media and technologies, if this new technology is to be used wisely and effectively. The central research question is the value of tracked, immersive visual displays over non-immersive simulations. The paper will provide a brief overview of existing VR research on training and transfer, education, and procedural, cognitive and maintenance training. It will close with an examination of important future issues: augmented reality, networked VR, edutainment, authoring systems, and equity.
What is VR?
There really are two kinds of VR, although in some ways they are complementary and not really distinguishable. The two basic varieties are sensory immersive VR and text-based networked VR. This paper will deal mainly with visually immersive VR, that makes your view of the world change when you move your head, and call text-based networked VR "Cyberspacen, to distinguish it pragmatically here. Although both are very useful for education and training, Cyberspace is better handled as an aspect of distance learning (Hunter, 1993). Another variety of VR, desktop VR or "fish tank VR~is not immersive (Ware, Kevin, and Kellogg, 1993), and so it is treated as another fo rm of simulation technology in this paper. It may have a special use fo r abstract visualization. In some sense, though, it is similar to immersive VR, except that it partitions a smaller amount of the surrounding sapce than wide f~eld of view VR. No kind of VR was explicitly mentioned by Nickerson and Zhodiates such a short time ago as 1988. Now there are many books available on the topic, ranging fr om popular anecdotal overviews (e.g. Krueger, 1991; and Rheingold, 1991; ), collections of research papers (Benedikt, 1991; Earnshaw, Gigante, & Jones, 1993; Ellis, 1991; VRAIS 93, 1993; and Wexelblat t, 1993), discussions of the social and educational implications of the technologies ( Laurel, 1991; Turkle, 1993), analyses of the educational implications (Middleton, 1992), overviews of the hardwar e and software technologies (Pimentel and Teixeira, 1992), and stories of homebrew VR ( Jacobson, 1994), or detailed scientific documentation (Kaslawsky, 1993 ).
Immersive VR
Immersive VR can be defined by its technology and its effects. Its primary effect is to place a person into a simulated environment that looks and feels to some degree like the real world. A person in this synthetic environment has a specific sense of self - location within it, can move her head and eyes to explore it, feels that the space surrounds her, and can interact with the objects in it. In immersive VR, simulated objects appear solid and have an egocentric location much like real objects in the real world They can be picked up, examined from all sides, navigated around, heard, smelled, touched, hefted, and explored in many sensory ways. The objects can also be autonomous (especially if they are other people) and interact with the virtual voyager, or respond to voice commands (Middleton and Boman, 1994). T he fundamental limitation to all these effects of course is in the computational technology that supports them.
The Technology of VR
The technology of VR is rapidly changing and improving within a very active research community (VRAIS'93, 1993). The following sections discuss some of the more important components of this technology for current working environments. The core technology that makes immersive Virtual Reality possible, the head mounted display (HMD), is progressing particularly fast, with projections common that eyeglass - size and weight HMDs will be available by the turn of the century (Chien and Jenkins, 1994).
Graphic not available
Figure 1. A picture of Joe Psotka getting immersed in a virtual world wearing an HMD.
HMD: The essential ingredient of VR is a tracked head - mounted display (HMD) that lets you see new views the visual world as you move your head. Wearing an HMD, one can look around and see the rest of the simulated world just like in the real world. Current image generation computers are limited in their ability to create a realistic, changing world. Special image generators cost hundreds of thousands of dollars, and the special lightweight, high-resolution displays can be equally expensive. Current microcomputers can realistically generate only a few thousand polygon s per second, while it has been estimated that nearly a billion polygons per second may be needed for near realism. These limitations not only lead to low resolution and cartoon - like shapes, they also lead to long lags of hundreds of milliseconds between changes in the head position and updates of the display. Narrow fields of view (often about half the normal field of view of 180 degrees) lead distortions of perceived space, to inaccurate self - localization (Psotka, Davison, and Lewis, 1993), errors in the judgment of distances (Henry and Furness, 1993), and simulator sickness (feelings of discomfort that can range from mild eyestrain and headaches to nausea and vomiting).
Tracking. An unobtrusive tracking mechanism, (magnetic, mechanical, infrared, gyroscopic, sound, or based on many innovative alternatives) registers any head motion and provides the signals to a computer to make the required changes in viewpoint in the modeled display. When your head moves, the visual scene changes. The result is a change of viewpoint just as if the eyes and head had moved in the virtual world In advanced and expensive systems, when your eyes move, then the scene changes. Such eye tracking is often used to provide a more detailed "fovea" or Area Of Interest (AOI) display (Warner, Serfoss, and Hubbard, 1993) of high resolution imagery that tracks the viewpoint. Any of these tracked displays usually result in a compelling sense of "being there", of being immersed in the simulation as if it is a real world. Long lags between any user's action and the resulting computed change in the display unfortunately often destroy this illusion and can lead to simulator sickness.
Gestures and Force Feedback: Gloves to gesture and interact with objects, and force - reflective feedback all all add to the compellingness of this experience. They add to the willingness to suspend disbelief that it takes to become immersed, but the main core of the experience is still primarily visual. Tactile reinforcement of the presence of an object, its shape, weight, solidity, and texture, adds considerably to the experience. Force feedback about the collisions with objects is a fundamental aid to navigation in VR: It prevents you from going through walls and floor, and other objects. Otherwise such sudden unnatural transitions often lead to disorientation and confusion. Gestures based on sensing of hand position and shape provide a natural means for interacting and communicating with the computer. For instance, one can select a distant object simply by pointing at it, Sometimes this selection is facilitated by having a ray extrude from a finger to the object. Others have suggested that one should be able to select objects by throwing something at them.
Stereo sound. Localizing objects from stereo sound adds to the sense of presence and immersion.
Voice Synthesis and recognition: Voice input and output capabilities are progressing rapidly and may soon be added to general VR environments, but remain currently largely unexploited. Magee (1994) has used them effectively in a VR training simulator for Navy ship commanders. Middleton and Boman ( 1994) have conducted a practically and theoretically ground breaking study of the conditions in a VR environment where voice recognition is useful. They observed that voice is best used for discrete changes in the environment, such as "Put me near object X", but not as good for continuously varying dynamic dimensions such as the direction or speed of one's flight.
Smell: There are many different ways to use odors to create a striking sense of presence. The technology of delivering odors is well-developed (Varner, 1993), in trials at Southwest Research Institute. The odors are all Food and Drug Administration approved and delivered at low concentration. The system uses a microencapsulation technique that can be dry packaged in cartridges that are safe and easy to handle. Human chemical senses such as taste and smell create particularly salient memories. They are also useful for alerting u s to danger, sexual arousal, and emotional experience.
The Psychological Experience of Immersion
In spite of the many technological limitations, many VR environments easily create a compelling sense of "being there", of presence or immersion. The psychological and human interface issues that affect immersion are beginning to be analyzed by several experimenters (Barfield and Weghorst, 1993; Psotka and Davison, 1993; Psotka and Calvert, 1994; Slater and Usoh, 1993). Clearly the burdensome equipment and limited motion often stir feelings of claustrophobia t o reduce the sense of immersion, and open the way to simulation sickness (cf. Kennedy, Lane, Lilienthal, Berbaum, and Hettinger, 1992). Immersion seems to be facilitated by the ability to control attention and focus on the new VR to the exclusion of the real world. Being able to see parts of one's own body, even in cartoon form, adds to the experience. It also depends on the use of a good visual imagination . It seems that people bring as much to the experience as the technology does. There is a great range of individual differences in the experience of immersion in VR environments. The technological limitations are largely responsible, but temperamental differences among individuals result in different reactions to these limitations. Perhaps if the technological limitations of burdensome equipment, lack of detail, and slow computers were overcome, these individual differences would disappear. But some difficulty may still remain to destroy the illusion, because voyagers will always possess the knowledge that it is all virtual. Even slight disturbances in the VR environment, such as obtrusively measuring heartrate, destroys the experience (Psotka and Calvert, 1994; See Figure 2.). Many of the limitations on the experience of VR are rapidly being reduced, but even the very limited capabilities currently available result in a powerful sense of direct engagement with the environment.
SOURCE: http://205.130.63.7/its.html *NOTE* This link is very inconsistent in its availability.