Virtual Reality vs. Immersive Environments: Choosing the Right Computer Interface for the Future
Evolution of Technology
Dr. D. Onieal
April 20, 1994
Introduction to Human-Computer Interface Design
Whether technology serves us by delivering information, providing services, or producing goods, it is always manifested in a physical form. Therefore, it is often necessary for us to interact with technology in a physical manner. By far, one of our most powerful expressions of technology is the computer. Because present interaction with computers demands a constant alternating succession of input and output of information, the physical elements of this interaction demand great attention in order to be successful.
To address this interaction, three sub-fields of study concerned with how humans physically interact with the computer have arisen: ergonomics, human factors, and human-computer interaction. While ergonomics deals with the physical shape of the machine, and human factors deals with physiological concerns, human-computer interaction looks at the cross-relations of computer science, psychology, and design in order to evaluate and improve the way we use computers. Human-computer interaction professionals often design and test computer interfaces, that is, the physical tools that enable the exchange of information.
In the past, relations between humans and computers have taken place on the level of the machine. Information, in the binary format of zeroes and ones, was fed to the computer with switches, or later with punch cards (Knuth 1980). Eventually "languages" were constructed in which word-like instructions, each representing a collection of instructions in binary code, could be typed in and fit together in order to instruct the computer to follow a program of computational events (Knuth 1980). The use of text was a great advance in simplifying the input and output of data and operations on that data, a step towards the manner in which humans interact with each other.
Presently, humans control computers with the use of some type of terminal. The average terminal has a keyboard for inputting alpha-numeric data, a video display for the output of visual information, and often an input device such as a mouse or trackball for controlling an on-screen cursor. This control environment holds for relatively affordable personal computers through the most powerful supercomputers. The amount of processing power differs, but the exchange of information occurs on the same level.
While text-based interfaces reigned for about twenty years and are still in widespread use, graphic-based interfaces have made another leap in simplifying the input and output processes. Graphic user-interfaces, or GUIs, employ icons and other graphic devices to present information and accept commands in a more robust fashion. Yet, these graphic user-interfaces still rely on the same basic terminal hardware of the past. Because of this consistency, humans continue to use the same perceptual habits to interact with computers: the eyes perceive the output from the video display and the hands provide the input by way of the keyboard and pointing device.
The responsibility of tasks that were once performed by the user has shifted to the computer. Donald Knuth uncovers the reasons for the past situation:
Mathematicians were so conscious of efficiency considerations that they could not imagine wasting any extra computer time for something a programmer could do by himself (Knuth 1980).
Today's computers are more powerful then ever, and the software designed for them encompasses a greater variety of tasks performed in novel new ways. Interfaces have improved necessarily to accommodate the increased throughput of information and the control of automated tasks once executed by humans. In many contemporary chores the older text-based systems execute poorly or simply fail. GUIs are not only more efficient but necessary. Furthermore, where interfaces were previously crippled by their inability to display graphics, the flat screen of GUIs is crippled by its inability to involve the user more fully (Walker 1990).
The future of computer interfaces will reflect a continuation of this advancing trend by expanding perceptual access to information in an attempt to reconcile ease of use with increased computing needs and capability.
Virtual Reality describes, for some, the ultimate interface between human and computer. Using Virtual Reality, or VR, the user's senses are fed perceptual material exclusively from the computer. This feedback from the computer comprises a grand array of sensory information compared to traditional GUIs. The intention is that enough realistic information will be presented to the user so that another set of surroundings will be perceived, one that is virtually real. VR systems of today consist of devices worn on the body that generate the virtual world. Goggles display three-dimensional, stereoscopic images while blocking out peripheral distractions. Headphones generate three-dimensional, binaural sound (Fisher 1990). A combination of sensors and solenoid actuators worn on the skin pick up user's body movements while producing proprioceptive tactile and force feedback (Larijani 1994). Olfactory and gustatory senses may also be addressed through the emission of substances from within a helmet (Larijani 1994).
Another view on the future of the computer interface says that the machinery should not be strapped to the person's body, but instead should surround the user naturally, as in a room of one's house. These interfaces are referred to as "immersive environments." Achieving the same virtual-space effect in a room requires apparatuses such as large video screens to envelope direct and peripheral vision, and three-dimensional or surround sound (Fisher 1990). Although the room itself may comprise the environment, the illusion of existing within another space may be acheived through media such as holography. Likewise, objects in the room may respond with amplified mannerisms, such as a book that acts like a hypertext document, allowing the user to navigate in a non-linear mode, following a chosen thread of information.
Immersion is an extension of the technique known as information hiding, where computing is done behind the scenes, insulating the user from the computing equipment (Nielson 1993). The user, by virtue of being inside the computer, does not form the otherwise obvious preconception that he or she is interacting with a computer. The primary functional difference between body-mounted VR schemes and immersive environments is that VR tries to replace conventional perceptual input with alternate, computer supplied perceptual material, where immersive environments endeavor to complement the conventional environment, or at least to replace particular objects and actions within the present environment.
Both body-mounted virtual reality devices and immersive environments belong to the same general category of interfaces known as cyberspace systems. John Walker of the software company Auto desk defines the cyberspace experience as "...one that provides users a three-dimensional interaction experience that includes the illusion they are inside a world rather than observing an image (Walker 1990)." Most professionals in the field of interface design agree that future interfaces will involve the user on the level of cyberspace, and that virtual reality will compete with immersive environments as the interface scheme of the future. Contrasting each as they will someday effect how humans use computers may reveal hints about their future success.
Computers in the twentieth century facilitate faster and easier communication than ever in history. From the arrival of facsimile machines and inter-office electronic mail to video teleconferencing and world-wide multimedia exchanges over the Internet, the transfer of ideas now occurs in a larger variety and with greater bandwidth. This increased variety and bandwidth of transmission genres must be presented in a manner that corresponds to the way people communicate naturally. If a lag in transmission delays the signal or if the resolution of the signal on the receiving end is poor, users will have to adopt unnatural habits to compensate for technology. The interface, therefore, must be sufficiently robust to expedite communication with the machine so that the machine can accurately relay the information to the other party.
Communication between parties with a body-mounted virtual reality system would necessitate that both parties operate inside the same virtual space, since each party is insulated from all other spaces. In some European and Latin American countries, touching is more common in interpersonal communication an area where sensors and actuators in contact with the skin would have an advantage over a video teleconferencing-like room environment. On the other hand, since the immersive environment allows the user to effectively communicate within two realms, the real one and the virtual one, the immersive environment eases access to persons in both spaces.
If either interface method tries to include communication among its functions, it will have to provide natural ways for users to express themselves, taking in to account all the different ways in which people communicate, i.e., languages, gestures, touch, and drawing pictures for example.
People not only like to communicate across great distances, they also like to perform work remotely. The 1990's ushered in the wider acceptance of telecommuting working from home and communicating with others using a computer. In the future it will become possible, and sometimes necessary, to perform more physical tasks remotely. Prime examples include dangerous industrial work and undersea or outerspace operations. Devices have been developed to enable persons to operate controls which in turn operate remote machinery to perform a corresponding duty. In these situations, the ability to successfully perform the remote ask depends on the amount of control and the effectiveness of feedback a system generates. When the system functions successfully in this fashion, the action is referred to as telepresence (Fisher 1990).
Telepresence systems today naturally fall under the category of virtual reality, since most machine controls must be operated by the hands. However, other interface technologies such as speech recognition currently develop in parallel. Using these alternate interfaces may decrease the reliance upon body-mounted equipment to execute remote actions. Still, few foreseeable interfaces accurately relay the agility and dynamic qualities of the human body, much less improve upon it.
Usability vs. Control
An overarching relationship in human-computer interface design says that ease of use is indirectly proportional to powerful and direct use (Nielson 1993). For example, a menu-driven interface may be easy to use, but may force the user to navigate through many menus to reach the desired function (the "voice mail phenomenon"). On the other hand, an interface that presents all of the system's functions simultaneously may present too much information for the user to comprehend easily, although an expert user will know at once where to proceed (Larijani 1994). The weight that is shifted to and fro to balance this equation is learning. In general, the more powerful the system, the more learning required; the more intuitable the interface, the less learning required.
The advantage of immersive environments in this relationship is the already familiar room-like environment. Alternately, the familiarity could be a disadvantage because endowing new behavior to old objects will confuse the user (Tognazzini 1992). For example, a chair that provides tactile feedback might scare someone who thought they were simply sitting in an ordinary chair.
Because a virtual reality system could model any environment, the familiar room environment could be simulated. In this situation, the user would probably assume this virtual environment would behave differently (Tognazzini 1992). A VR system could conceivably present an entirely new environment, perhaps one implementing revolutionary control methods. But in this case the user would face a much steeper learning curve before arriving at a comfortable working level due to the lack of familiarity. Which paradigm works more effectively in balancing ease and power depends upon the particular implementation, but VR probably has the advantage in regard to pure variety of original spaces.
Empowering the User
Whether for business or personal use, the computer brings a subjective feeling of power to the user, and this is certainly part of its appeal. This feeling may be a reaction to the speed, the graphic presentation, or the simple ability to control such the machine's operations so completely. Virtual reality, with its infinite number of virtual worlds, immediately conjures up thoughts of empowering situations. But as in the usability vs. control equation outlined above, an incredibly empowering situation may be frustratingly difficult to control intelligently. Immersive environments may better act as an intermediate step in empowering the user with a more robust interface within a comfortable, familiar environment.
To Interface or Not
Presently, people view computers as powerful machines that can increase productivity and improve life in general. Once computer literacy becomes universal, however, the novelty and prestige of computer skills and knowledge may fall from the high seat of respectability it now claims. In his essay, John Anthony Bailo points out the limited value of interfaces in general:
People will stop looking at the benefits of direct interaction with a computer and start looking at its pitfalls and displeasures. Background processing - the stuff that mainframe computers do well - will resurface.... Look for people to gain status by taking PCs off their desks and saying: "My computer works for me, I don't work on my computer (Bailo 1993)."
This view on human-computer interaction has resulted in the saying, "The best interface is no interface." Reducing the interface would cause a complementary reduction of the learning curve. Certainly, an immersive environment is nearer to this ideal than body-mounted devices.
Body-mounted devices presently account for a greater percentage of cyberspace systems because they are less expensive to develop (Larijani 1994). The devices are smaller and can be substituted individually as needed. Low cost enables their employment for entertainment purposes in arcades and for research in universities and other institutions.
Since they are not easily replaced, and therefore have potentially high costs, existent immersive environments suit permanent installations well, such as in museums. For example, The Boston Computer Museum places the visitor inside a two-story working model of a computer; an effective yet expensive use of interface technology. An exorbitant cost will certainly delay acceptance in the home market.
Advantages of body-mounted VR devices include easy storage when not in use. Otherwise, the need to "wear" these systems does not integrate well with present lifestyles.
People must first adapt to the vigorous, and at first, overwhelming, implications of these interfaces before they will be accepted in the home. Once in the home, immersive environments may be preferable to the clumsier body-mounted gear. Conceivably, the environment could be disabled, leaving a conventional room behind.
As a transitional technology, immersive environments are superior both because they provide a natural entry point for the uninterested or technophobic in the early stages of the technology, and because in the long run these environments are preferable to wearing body-mounted equipment. VR represents sensory technology advanced with little regard for how the human is using it. Additionally, immersive environments can use better functioning equipment because the devices are not so severly limited by scale.
As an interface for the long run, immersive environments may reign because users may not accept the more cumbersome body-mounted components, preferring the further development of immersive environments.
Body-mounted virtual reality systems will find homes in areas as diverse as defense and entertainment; in the former because convenience has a lower priority than in commercial use, and in the latter because computer devices are often conceived of as a novel symbols of high technology, and therefore marketable.
In the further future, however, we can only guess as to how we will physically interact with the computer. Author Howard Rheingold foresees that cyberspace systems will not only be designed for the ways in which humans behave, the systems may actually change the way humans behave, and therefore will be designed on their own terms (Rheingold 1990). The goal then will be not only to improve the manner of interaction between human and machine, but to involve both in a symbiotic development.
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