# Definition of "Wearable Computer"

Definition of what is meant by the term wearable computer, e.g. a definition of wearable computing.

Wearable Computer Definition taken from Steve Mann's Keynote Address entitled "WEARABLE COMPUTING as means for PERSONAL EMPOWERMENT" presented at the 1998 International Conference on Wearable Computing ICWC-98, Fairfax VA, May 1998

Steve Mann
University of Toronto,
May 12, 1998
Wearable computing facilitates a new form of human--computer interaction comprising a small body--worn computer (e.g. user--programmable device) that is always on and always ready and accessible. In this regard, the new computational framework differs from that of hand held devices, laptop computers and personal digital assistants (PDAs). The always ready'' capability leads to a new form of synergy between human and computer, characterized by long-term adaptation through constancy of user--interface.

# What is a wearable computer

A wearable computer is a computer that is subsumed into the personal space of the user, controlled by the user, and has both operational and interactional constancy, i.e. is always on and always accessible. Most notably, it is a device that is always with the user, and into which the user can always enter commands and execute a set of such entered commands, and in which the user can do so while walking around or doing other activities. The most salient aspect of computers, in general, (whether wearable or not) is their {\em reconfigurability} and their {\em generality}, e.g. that their function can be made to vary widely, depending on the instructions provided for program execution. With the wearable computer (WearComp), this is no exception, e.g. the wearable computer is more than just a wristwatch or regular eyeglasses: it has the full functionality of a computer system but in addition to being a fully featured computer, it is also inextricably intertwined with the wearer. This is what sets the wearable computer apart from other wearable devices such as wristwatches, regular eyeglasses, wearable radios, etc.. Unlike these other wearable devices that are not programmable (reconfigurable), the wearable computer is as reconfigurable as the familiar desktop or mainframe computer. Wearable computing will now be formally defined in terms of its three basic modes of operation and its six fundamental attributes.

## Operational modes of wearable computing

There are three operational modes in this new interaction between human and computer:
• Constancy: The computer runs continuously, and is always ready'' to interact with the user. Unlike a hand-held device, laptop computer, or PDA, it does not need to be opened up and turned on prior to use. The signal flow from human to computer, and computer to human, depicted in Fig 1a runs continuously to provide a constant user--interface.
• Augmentation: Traditional computing paradigms are based on the notion that computing is the primary task. Wearable computing, however, is based on the notion that computing is NOT the primary task. The assumption of wearable computing is that the user will be doing something else at the same time as doing the computing. Thus the computer should serve to augment the intellect, or augment the senses. The signal flow between human and computer is depicted in Fig 1b.
• Mediation: Unlike hand held devices, laptop computers, and PDAs, the wearable computer can encapsulate us (Fig 1c). It doesn't necessarily need to completely enclose us, but the concept allows for a greater degree of encapsulation than traditional portable computers. There are two aspects to this encapsulation:
• Solitude: It can function as an information filter, and allow us to block out material we might not wish to experience, whether it be offensive advertising, or simply a desire to replace existing media with different media. In less severe manifestations, it may simply allow us to alter our perception of reality in a very mild sort of way.
• Privacy: Mediation allows us to block or modify information leaving our encapsulated space. In the same way that ordinary clothing prevents others from seeing our naked bodies, the wearable computer may, for example, serve as an intermediary for interacting with untrusted systems, such as third party digital anonymous cash cyberwallets''. In the same way that martial artists, especially stick fighters, wear a long black robe that comes right down to the ground, in order to hide the placement of their feet from their oponent, wearable computing can also be used to clothe our otherwise transparent movements in cyberspace. Although other technologies, like desktop computers, can help us protect our privacy with programs like Pretty Good Privacy (PGP), the achilles tendon of these systems is the space between us and them. It is generally far easier for an attacker to compromise the link between us and the computer (perhaps through a so-called trojan horse or other planted virus) than it is to compromise the link between our computer and other computers. Thus wearable computing can be used to create a new level of personal privacy because it can be made much more personal, e.g. so that it is always worn, except perhaps during showering, and therefore less likely to fall prey to covert attacks upon the hardware itself. Moreover, the close synergy between the human and computers makes it harder to attack directly, e.g. as one might peek over a person's shoulder while they are typing, or hide a video camera in the ceiling above their keyboard. Furthermore, the wearable computer can take the form of undergarments that are encapsulated in an outer covering or outerwear of fine conductive fabric to protect from an attacker looking at radio frequency emissions. The actual communications between the wearer and other computers (and thus other people) can be done by way of outer garments, which contain conformal antennas, or the like, and convey an encrypted bitstream.
Because of its ability to encapsulate us, e.g. in embodiments of wearable computing that are actually articles of clothing in direct contact with our flesh, it may also be able to make measurements of various physiological quantities. Thus the signal flow depicted in Fig 1a is also enhanced by the encapsulation as depicted in Fig 1c. To make this signal flow more explicit, Fig 1c has been redrawn, in Fig 1d, where the computer and human are depicted as two separate entities within an optional protective shell, which may be removed or partially removed if a mixture of augmented and mediated interaction is desired.
Wearable computing is a framework for enabling various degrees of each of these three fundamental modes of operation. Collectively, the space of possible signal flows giving rise to this entire space of possibilities, is depicted in Fig 2.

While individual embodiments of wearable computing may use some mixture of these concepts, the signal path depicted in Fig 2 provides a general framework for comparison and study of these systems. The signal paths typically each, in fact, include multiple signals, hence multiple parallel signal paths are depicted in this figure to make this plurality of signals explicit.

## The six attributes (six signal paths) of wearable computing

There are six informational flow paths associated with this new human--machine synergy. These signal flow paths are, in fact, attributes of wearable computing, and are described, in what follows, from the human's point of view:
1. UNMONOPOLIZING of the user's attention: it does not cut you off from the outside world like a virtual reality game or the like. You can attend to other matters while using the apparatus. It is built with the assumption that computing will be a secondary activity, rather than a primary focus of attention. In fact, ideally, it will provide enhanced sensory capabilities. It may, however, mediate (augment, alter, or deliberately diminish) the sensory capabilities.
2. UNRESTRICTIVE to the user: ambulatory, mobile, roving, you can do other things while using it'', e.g. you can type while jogging, etc.
3. OBSERVABLE by the user: It can get your attention continuously if you want it to. Almost--always--observable: within reasonable limitations (e.g. that you might not see the screen while you blink or look away momentarily) the output medium is constantly perceptible by the wearer.
4. CONTROLLABLE by the user: Responsive. You can grab control of it at any time you wish. Even in automated processes you can manually override to break open the control loop and become part of the loop at any time you want to (example: a big Halt button you want as an application mindlessly opens all 50 documents that were highlighted when you accidently pressed Enter'' would make a computer more CONTROLLABLE. Infinitely--often--controllable: the constancy of user--interface results from almost--always observability and infinitely--often controllability in the sense that there is always a potential for manual override which need not be always exercised.
5. ATTENTIVE to the environment: Environmentally aware, multimodal, multisensory. (As a result this ultimately gives the user increased situational awareness).
6. COMMUNICATIVE to others: Can be used as a communications medium when you want it to. Expressive: allows the wearer to be expressive through the medium, whether as a direct communications medium to others, or as means of assisting the production of expressive media (artistic or otherwise).
Implied by the above six properties is that it must also be:
• CONSTANT: Always ready. May have sleep modes'' but never dead''. Unlike a laptop computer which must be opened up, switched on, and booted up before use, it is always on and always running.
• PERSONAL: Human and computer are inextricably intertwined.
• PROSTHETIC: You can adapt to it so that it acts as a true extension of mind and body; after time you forget that you are wearing it.
• ASSERTIVE: can have barrier to prohibition or to requests by others for removal during times when you wish such a barrier. This is in contrast to laptop computer in briefcase or bag that could be separated from you by a please leave all bags and briefcases at the counter'' policy of a department store, library, or similar establishment.
• PRIVATE: others can't observe or control it unless you let them. Others can't determine system status unless you want them to, e.g. clerk at refund counter in department store where photography is prohibited can't tell whether or not you are transmitting wireless video to a spouse for remote advice, in contrast to camcorder technology where it is obvious you are taking a picture when you hold it up to your eye.
Note that a computer mediation device with sufficient bandwidth can synthesize or even heighten the augmentational aspects. For example a sufficiently ATTENTIVE computer can sustain a sufficient illusion of being UNMONOPOLIZING that it could encapsulate the user and still provide the same experience as system running in the augmentational mode of operation. Similarly, a sufficiently COMMUNICATIVE machine, especially if machine'' is broadened to include mechanical mediation devices such as motorized exoskeletons, can synthesize the UNRESTRICTIVE attribute.

# Fundamental issues of wearable computing

The most fundamental paradigm shift that wearable computing has to offer is that of personal empowerment. In order to fully appreciate the magnitude of this paradigm shift, some historical examples of tools of empowerment will now be described to place wearable computing in this historical context.

## Historical context

In early civilization, individuals were all roughly equal, militarily. Wealth was generally determined by how many head of cattle, or how many mounts'' (horses) a person owned. In hand--to--hand combat, fighting with swords, each individual was roughly an equal. Since it was impossible to stay on a horse while fighting, horses provided little in the way of military power, so that even those too poor to afford to keep a horse were not at a tremendous disadvantage to others from a fighting standpoint.

It was the invention of the stirrup, however, that radically changed this balance. With the stirrup, it became possible to stay on a horse while fighting. Horses and heavy armour could only be afforded by the wealthy, and even a large group of unruly peasants was no match for a much smaller group of mounted cavalry. However, toward the middle ages, more and more ordinary individuals mastered the art of fighting on horseback, and eventually the playing field leveled out.

Then, with the invention of gunpowder, the ordinary civilian was powerless against soldiers or bandits armed with guns. It was not until guns became cheap enough that everyone could own one --- as in the old west''. The Colt 45, for example, was known as the equalizer'' because it made everyone roughly equal. Even if one person was much more skilled in its use, there would still be some risk involved in robbing other civilians or looting someone's home.

### The shift from guns to cameras and computers

In today's world, the hand gun has a lesser role to play. Wars are fought with information, and we live in a world in which the appearance of thugs and bandits is not ubiquitous. While there is some crime, we spend most of our lives living in relative peace. However, surveillance and mass media have become the new instruments of social control. Department stores are protected with security cameras rather than by owners keeping a shotgun under the counter or hiring armed guards to provide a visible deterrent. While some department stores in rough neighbourhoods may have armed guards, there has been a paradigm shift where we see less guns and more surveillance cameras.

### The shift from draconian punishment to micro management

There has also been a paradigm shift, throughout the ages, characterized by a move toward less severe punishments, inflicted with greater certainty. In the middle ages, the lack of sophisticated surveillance and communications networks meant that criminals often escaped detection or capture, but when they were captured, punishments were extremely severe. Gruesome corporeal punishments where criminals might be crucified, or whipped, branded, drawn and quartered, and then burned at the stake, were quite common in these times.

The evolution from punishment as a spectacle in which people where tortured to death in the village square, toward incarceration in which people were locked in a cell, and forced to attend church sermons, prison lectures, etc., marked the first step in a paradigm shift toward less severe punishments\cite{foucault}. Combined with improved forensic technologies like fingerprinting, this reduction in the severity of punishment came together with a greater chance of getting caught.

More recently, with the advent of so--called boot camp'', where delinquent youths are sent off for mandatory military--style training, the trend continues by addressing social problems earlier before they become large problems. This requires greater surveillance and monitoring, but at the same time is characterized by less severe actions taken against those who are deemed to require these actions. Thus there is, again, still greater chance of being affected by smaller punishments.

If we extrapolate this trend, what we arrive at is a system of social control characterized by total surveillance and micro--punishments. At some point, the forces applied to the subjects of the social control are too weak to even justify the use of the word punishment'', and perhaps it might be better referred to as micro management''.

This micro management'' of society may be effected by subjecting the population to mass media, advertising, and calming music played in department stores, elevators, and subway stations.

Surveillance is also spreading into areas that were generally private in earlier times. The surveillance cameras that were placed in banks have moved to department stores. They first appeared above cash registers to deal with major crimes like holdups. But then they moved into the aisles and spread throughout the store to deal with petty theft. Again, more surveillance for dealing with lesser crimes.

In the U.K., cameras installed for controlling crime in rough areas of town spread to low crime areas as well, in order to deal with problems like youths stealing apples from street markets, or patrons of pubs urinating on the street. The cameras have even spread into restaurants and pubs --- not just above the cash register, but throughout the pub, so that going out for pints, one may no longer have privacy.

Recently, electronic plumbing technology, originally developed for use in prisons, for example, to prevent all inmates from flushing the toilets simultaneously, has started to be used in public buildings. The arguments in favor of it go beyond human hygiene and water conservation, as proponents of the technology argue that it also reduces vandalism. Their definition of vandalism has been broadened to include deliberately flooding a plumbing fixture, and deliberately leaving faucets running. Thus, again, what we see is greater certainty of catching or preventing people from committing lesser transgressions of the social order.

One particularly subtle form of social control using this technology, is the new hands free electronic showers developed for use in prisons where inmates would otherwise break off knobs, levers, and pushbuttons. These showers are just beginning to appear in government buildings, stadiums, health clubs, and schools. The machine watches the user, from behind a tiled wall, through a small dark glass window. When the user steps toward the shower, the water comes on, but only for a certain time, and then it shuts off. Obviously the user can step away from the viewing window, and then return, to receive more water, and thus defeat the timeout feature of the system, but this need to step away and move back into view is enough of an irritant as to effect a slight behavioural modification of the user. Thus what we see is that surveillance has swept across all facets of society, but is being used to deal with smaller and smaller problems. From dealing with mass murderers and bank robbers, to people who threaten the environment by taking long showers, the long arm of surveillance has reached into even the most private of places, where we might have once been alone. The peace and solitude of the shower, where our greatest inspirations might come to us, has been intruded upon with not a major punishment, but a very minor form of social control, too small in fact to even be called a punishment.

These surveillance and social control systems are linked together, often to central computer systems. Everything from surveillance cameras in the bank, to electronic plumbing networks is being equipped with fiber optic communications networks. Together with the vast array of medical records, credit card purchases, buying preferences, etc., we are affected in more ways, but with lesser influence. We are no longer held at bay by mounted cavalry. More often than being influenced by weapons, we are influenced in very slight, almost imperceptible ways, for example, through a deluge of junk mail, marketing, advertising, or a shower that shuts off after it sees that we've been standing under it for too long.

While there are some (the most notable being Jeremy Bentham\cite{foucault}) who may argue that a carefully managed society results in maximization of happiness, there are others who argue that the homogenization of society is unhealthy, and reduces humans to cogs in a larger piece of machinery, or at the very least, results in a certain loss of human dignity. Moreover, just as nature provides biodiversity, many believe that society should also be diverse, and people should try to resist ubiquitous centralized surveillance and control, particularly to the extent where it homogenizes society excessively. Some argue that micromanagement and utilitarianism, in which a person's value may often be measured in terms of usefulness to society, is what led to eugenics, and eventually to the fascism of Nazi Germany. Many people also agree that, even without any sort of social control mechanism, surveillance, in and of itself, still violates their privacy, and is fundamentally wrong.

As with other technologies, like the stirrup and gunpowder, the electronic surveillance playing field is also being leveled. The advent of the low-cost personal computer has allowed individuals to communicate freely and easily among themselves. No longer are the major media conglomerates the sole voice heard in our homes. The World Wide Web has ushered in a new era of underground news and alternative content. Thus centralized computing facilities, the very technology that many perceived as a threat to human individuality and freedom, has given way to low cost personal computers that many people can afford. This is not to say that home computers will be as big or powerful as the larger computers used by large corporations or governments, but simply that if a large number of people have a moderate degree of computational resources, there is a sense of balance in which people are roughly equal in the same sense that two people, face to face, one with a 0.22 calibre handgun and the other with a Colt 0.45 are roughly equal. A large bullet hole or a small one, both provide a tangible and real risk of death or injury.

It is perhaps modern cryptography that makes this balance even more pronounced, for it is so many orders of magnitude easier to encrypt a message than it is to decrypt it. Accordingly, many governments have defined cryptography as a munition and attempted, with only limited success, to restrict its use, and some have even defined it as a munition.

### Fundamental issues of wearable computing

The most fundamental issue in wearable computing is no doubt that of personal empowerment, through its ability to equip the individual with a personalized, customizable information space, owned, operated, and controlled by the wearer. While home computers have gone a long way to empowering the individual, they only do so when the user is at home. As the home is perhaps the last bastion of space not yet touched by the long arm of surveillance --- space that one can call one's own, the home computer, while it does provide an increase in personal empowerment, is not nearly so profound in its effect as the wearable computer which brings this personal space --- space one can call one's own --- out into the world.

Although wearable computing, in the most common form we know it today (miniature video screen over one or both eyes, body worn processor, and input devices such as a collection of pushbutton switches or joystick held in one hand and a microphone) was invented in the 1970s for personal imaging applications, it has more recently been adopted by the military in the context of large government--funded projects.

However, as with the stirrup, gunpowder, and other similar inventions, it is already making its way out into the mainstream consumer electronics arena.

An important observation to make, with regards to the continued innovation, early adopters (military, government, large multinational corporations), and finally ubiquity, is the time scale. While it took hundreds of years for the stirrup to be adopted by the masses, and tens of years for guns to be adopted by the masses, the spread of computer technology must be measured in computer years. As the technology moves faster, the military is losing its edge. We are entering an era in which consumer electronics is surpassing the technological sophistication of some military electronics. Personal audio systems like the SONY Walkman are just one example of how the ubiquity and sophistication of technology feed upon each other to the extent that the technology begins to rival, and in some ways, exceed, the technical sophistication of the limited--production military counterparts such as two--way radios used in the battlefield.

Consumer technology has already brought about a certain degree of personal empowerment, from the portable cassette player that lets us replace the music piped into department stores with whatever we would rather hear, to small hand held cameras that capture police brutality and human rights violations. However, wearable computing is just beginning to bring about a much greater paradigm shift, which may well be equivalent in its impact to the invention of the stirrup, or that of gunpowder. Moreover, this leveling of the playing field may, for the first time in history, happen almost instantaneously, should the major consumer electronics manufacturers beat the military to raising this invention to a level of perfection similar to that of the stirrup or modern handguns. If this were to happen, this decreasing of the time scale over which technology diffuses through society will have decreased to zero, resulting in a new kind of paradigm shift that society has not yet experienced.

## Aspects of wearable computing and personal empowerment

There are several aspects and affordances of wearable computing. These are:
• Photographic memory: Perfect recall of previously collected information.
• Shared memory: In a collective sense, two or more individuals may share in their collective consciousness, so that one may have a recall of information that one need not have experienced personally.
• Connected collective humanistic intelligence: In a collective sense, two or more individuals may collaborate while one or more of them is doing another primary task.
• Personal safety: In contrast to a centralized surveillance network built into the architecture of the city, a personal safety system is built into the architecture (clothing) of the individual.
• Tetherless operation: Wearable computing affords and requires mobility, and the freedom from the need to be connected by wire to an electrical outlet, or communications line.
• Synergy: Rather than attempting to emulate human intelligence in the computer, as is a common goal of research in Artificial Intelligence (AI), the goal of wearable computing is to produce a synergistic combination of human and machine, in which the human performs tasks that it is better at, while the computer performs tasks that it is better at. Over an extended period of time, the wearable computer begins to function as a true extension of the mind and body, and no longer feels as if it is a separate entity. In fact, the user will often adapt to the apparatus to such a degree, that when taking it off, its absence will feel uncomfortable, in the same way that we adapt to shoes and clothing to such a degree that being without them most of us would feel extremely uncomfortable whether in a public setting, or in an environment in which we have come to be accustomed to the protection that shoes and clothing provide. This intimate and constant bonding is such that the combined capabilities of the resulting synergistic whole far exceeds the sum of either. Synergy, in which the human being and computer become elements of each other's feedback loop, is often called Humanistic Intelligence (HI).
• Quality of life: Wearable computing is capable of enhancing day--to--day experiences, not just in the workplace, but in all facets of daily life. It has the capability to enhance the quality of life for many people.

http://wearcomp.org/wearcompdef.html