Is using a computer sometimes, literally, a pain in the neck? Do your eyes have trouble focusing on the screen? Does your upper arm ache from repeated strain on your mouse finger's tendon? I know mine do as I write this sentence. Physical stress is one of the physiological problems with the video display terminal operation. Ignoring my own advice to you in this chapter, I've been sitting here for five hours.
Are computers fun? Are they convenient? Does using one make you feel competent and in control? These are some of the psychological satisfactions of a "user friendly" tool. At the moment, my answers are no, yes, and yes.
But how frienly can a computer be, when "friend" is a social relationship? Are you talking more to computers and less to people? Or are you using the computer as a way to communicate, perhaps the way I'm talking to you via the World Wide Web. These are some of the social issues of ergonomics, the study of the human/technology interface. Most computer ergonomic research is micro-level. It studies the physiology and psychology of the immediate connection between computers and people.
The effects of the computer on the individual is often considered a technical question involving user-friendly interfaces between the person and the machine. Human factors research (as ergonomics is also called) is a relatively new field that looks at the match between the machine and the human being as a biological organism (Helander, et. al., 1984 ref). Cognitive factors of perception and learning are also taken into account in order to create interfaces that accomodate the user. A "good" interface is user- friendly; it meets human needs. But to understand the human/computer interaction we must consider what it is that human beings need.
The model of human needs developed by A. H. Maslow is one of several psychological approaches to the growth of human personalities. As shown in Figure 4-1, it represents an overlapping set of needs whose relative strengths vary according to individual situations and personalities. Basic biological needs are strongest determinents of our actions when we are children. As our personalities develop, the "higher" cognitive and psychological needs become more important. For example, we may ignore our hunger in order to finish a computer program before dinner. Maslow's thoery assumes a moral progression from personalities organized to satisfy immediate wants to those oriented towards acting responsibly in the social world. Using Maslow's model, we could ask how computer use satisfies or frustrates individual need. The physiological requirements of human beings -- food, shelter, and air are some of these -- are not usually directly met by computers. However, computers indirectly contribute to the production
The next two levels of need refer to peoples' social needs. Society provides for the safety and security of its members and gives them a sense of group membership. Social institutions like the family and social relationships like friendship provide a sense of love and belonging. Although a person can survive physically without others, that person's self-identification as a member of a social group is a basic part of his or her social nature. Computers act on this level of need through their effects on institutions and relationships.
The higher needs defined by Maslow are the individual psychological ones. Self-esteem is social insofar as the approval of others is a contributing factor, but self-esteem can also be personal. Self- actualization is the need to act on the basis of one's sense of self, and to feel that one's activities are successful in whatever terms one values. In a study of self-actualizing persons, Maslow found them
more efficient in perceiving reality, more accepting of themselves and others, more spontaneous in their relationships, with a tendency to centre on problems and their solution; to have a quality of privacy and detachment, and autonomy from cultural influences, a freshness of appreciation, a capacity for transcendence and oceanic feelings, a deep identification with humanity, more profound human attachments, a humorous and democratic character structure, and a rare capactiy to resolve moral dichotomies and dilemmas (Hampden- Turner, 1983 ref).
While all social theorists would agree with Maslow that individuals have biological, social, and psychological needs, not all would agree with his selection, or his priorities. There is great disagreement over what peoples' biological requirements are and where biology gives way to culture in defining them. Some theorists would add competition or territoriality to the list; others would argue about whether self-esteem is based on social status or on private, internal feelings of satisfaction. Others would question whether the needs for personal identity are "higher" than the social needs to fulfill the obligations and gain the benefits of group membership. Environmentalists would argue that there is a higher need to preserve and protect the earth for future generations; philosophers and theologians would make a case for an even higher level of spiritual need.
According to this perspective, the goal of ergonomics research is not to meet any individual needs, but to match humans with computers in ways that raise productivity. Improved comfort or user satisfaction are most important in cases where imporved satisfaction leads to productivity increases. Where there is a conflict between productivity and comfort, design choices will be made for productivity.
Northeastern's Office of Environmental Health and Safety provides links to information on office ergonomics containing current information on preventing physical problems.
A list of other Ergonomics servers can be found at UCSF/UCB Ergonomics Program
FIGURE 4-2. ERGONOMIC WORKSTATION PARAMETERS
Unless a workstation is to be used by only one person, furniture must be adjustable. Designs for the average man or woman are usually unsuitable for just about everybody except those few whose body proportions happen to be exactly average. For example, I am of average height for a woman when sitting down and of average height for a man when standing up. Before adjustable workstations were common my legs were "too long" and my body was "too short" for on-the-job comfort. From the perspective of ergonomics, variations in human proportions are a "given"; the designer's task is to make a machine that accomodates the variety in human form.
No amount of design, however, can change the fact that the human body did not evolve the ability to remain motionless for long periods of time. Frequent changes in position, and physical exercise, are both essential for maintaining muscle tone and avoiding stress and fatigue. Improvements in voice-operated computers may be the best way to match active humans to immobile machines. In the meantime, computer users and workstation designers are developing more awareness of the physical consequences of their work. "User friendly" hardware shouldn't give the user a pain in the neck. When you have the choice, you should plan your own work to avoid long sessions seated at a computer terminal. I find short walks and long backrubs ideal.
The productivity factor of most concern to designers of screen displays is the eye's ability to distinguish shapes. In addition to causing eyestrain, failure to make visual discriminations can result in higher error rates for whatever type of work is being done. Character fonts (the shape of letters and numbers) can be designed to improve people's recognition of individual characters. When characters are displayed as a pattern of small dots (pixels) on a screen, the greater the number of dots used, the greater the character's readability. In character fonts made in a 7x9 matrix (the smallest number of pixels for a readable European language character set) the following characters are commonly confused:
Improvements in display resolution include the use of color combinations (like the popular amber on black) that are easier on the eyes. Research on the physiology of color perception resulted in the recommendations in Table 3. Although the use of color in screen displays can reduce fatigue and be psychologically more interesting, about 8% of all males (and about one half of one percent of females) are colorblind to some extent, most commonly to red, green, or both (Birren, 1978).
Ergonomic factors in screen design include information about how people read. In English and other left to right languages, screens that present material from left to right are more successful than top to bottom ones. This applies as well to the number pad found on many terminals and calculators. When the numbers 7, 8, and 9 are on the top row, users make more errors than when the top row is 1, 2, and 3. Although many of our designs are "traditional", even experienced users adjust easily to a new layout and quickly improve their performance.
A final example of a visual discrimination problem built into a traditional design is the data entry form with little boxes for each letter. Filling in the boxes by hand takes 16% longer than it would to simply write the material on a straight line. Reading the boxes takes 28% longer than reading material written on a line. The boxes also result in a higher error rate when someone types from them onto a computer keyboard (Wright, 1984). The people who first designed forms with boxes probably thought they were matching human data recording techniques with the requirements of efficient keypunch machine operation. But microergonomic research showed us that an interface that doesn't match human perceptual requirements is less efficient for data processing.
According to recent research, VDT terminals meet the guidelines established by the American National Standards Institute for safe levels of exposure to low frequency radiation (Murray, 1984). However, because it is difficult to measure extremely low frequency electromagnetic fields (below 10 kHz), and because human neurological and cell processes occur in the 8-25 Hz range, scientists do not have enough evidence on the biological effects of VDT radiation in this range to conclude that they are harmless (Harvey, 1984).
Static buildup may also affect your mood. An imbalance of positively- charged ions in the air (as in the Santa Anna wind which sometimes blows across Southern California) can cause irritability and fatigue. A balance of negatively charged ions (as often found in mountaintop areas) are reportedly invigorating. Some research has found that negative ion generators reduce the frequency of headaches and make employees feel more comfortable and alert (Hawkins, 1984).
Terminals can be shielded to prevent emissions. Although the Computer and Business Equipment Manufacturers Association called the announcement of a VDT radiation shield an "irresponsible" appeal to the fears of people who know little about radiation ("Cbema...", 1985), an IBM report recommended shielding older terminals. It concluding that the newer ones were better designed and represent no hazard (VDT News March/April, 1985:4-7). People who are worried about the possible effects of display terminal radiation should also be concerned about their TV set. Doubling the distance between yourself and the screen will reduce your exposure to any possible emissions by 75%.
Women, whose reproductive organs are better protected by layers of body tissue, have also been studied for possible reproductive damage. Although clusters of problem pregnancies have been reported among VDT operators, the evidence has been insufficient to establish any radiation hazard. Physical stress, for example, might be a contributing factor in miscarriages. Several major studies are underway to evaluate any potential problems (VDT News, July/August, 1985:4-6). A large recent Finnish study of birth defects found no evidence that they were related to VDT use by the mothers (VDT News, Jan/Feb, 1985:12).
The possible health effect of VDT radiation remains an unresolved issue in ergonomic research, in public policy, and in computer design. Should the hazards finally be assessed as serious, shielding users from extremely low frequency emisions would become a social priority in computer technology. In 1985 the U.S. Congress concluded that there is insufficient evidence of risk to establish VDT regulations, but several states have passed laws doing so. Based on its best available information, the Human Factors Society proposed an American National Standard for Human Factors Engineering of Visual Display Terminal Workstations. For information on the current status of ergonomic recommendations, you should consult the current version of the standard.
Visual aids for lip readers included a computerized pair of eyeglasses which display a visual signal generated by a small voice analyzer. Designed as an aid to lip readers, the display distinguishes sounds which look deceptively alike. An anatomically correct talking head that can be used as a video screen reader is currently under development.
The most useful adaptive technology for blind computer users is the screen reader, which reads computer files and directories aloud. Not all files can be accessed by screen readers. For example, many cdrom directories are inaccessible. The widespread introduction of the GUIs (graphical User Interfaces) such as Microsoft Windows has created a challenge for adaptive technology designers and users. Windows are difficult for screen readers, despite some promising developments such as Georgia Tech's "Accessible X".
One design idea proposed in the 1980's for viewing low resolution graphs (though I haven't seen a resulting product) was a computerized tactile grid which allows the blind to "see" graphics output. A colleague reports that there is now a technology that allows special paper to be used in any laser printer. When heated, the graphical output is raised on the paper,
Screen readers can be connected to a text only web browser (like lynx) to allow blind web surfers to hear web pages. However, what lots of web pages sound like is:
image, image, click here for a great image, image, click our image mapAs more information moves onto the worldwide web, the design of accessible web pages has become an important social and ethical issue. In putting this book on the web, I have been trying different ways to provide alternatives to scanning in images of figures and tables. [but since I haven't had time to put in the tables and figures yet, you can't view or hear the results...maybe audio files would work as alternatives to graphics. %-) any ideas, anybody?]
The physical self is our experience of ourselves as a biological organism. If you wrote "I am six feet tall" or "I am hungry", you were describing yourself in this way. The computer/human interface influences this dimension of self-concept by changing our physical activities and physiological experiences. If your statements included a description of your roles ("a student", "a parent", "a vice-president"), your particular social relationships ("Mary's best friend), or your group identifications ("an American"), you were thinking of your social self. This dimension of the self is of most interest to sociologists. The feeling of self-esteem is part of the social self-concept.
In religious or mystical experiences people report an oceanic self that is part of the whole universe. If your sentences described your relationship to the sacred, you were describing this dimension of self concept. Many cultures encourage people to think of themselves in this way; ours tends to view mysticism outside of conventional religious institutions as a form of deviance. An oceanic sense of oneself as having special insight into or power over the universe can be considered medically a symptom of mental illness. It can also considered sacrilegeous by people who believe in God. Because the computer interface can heighten our feelings of connectedness and our feelings of power, some observers think the technology will encourage the oceanic self concept.
There is also a dimension of the self that thinks about its own existence. If you wrote a sentence like: "I am someone who thinks about who I am.", you were experiencing your reflexive self. Self-actualizing people are reflexive. They not only act in satisfying ways; they comprehend the meanings and consequences of their actions. Some psychologists think that, by reflecting on our experience of the computer/human interface, we will change our understanding of what it means to be human.
Jobs like air traffic controller are reportedly high stress occupations, but studies have shown air traffic controllers to suffer few physiological symptoms. They seem to enjoy the pace, responsbilities, and status of their jobs. However, they have little voice in decision-making or advancement into management, which is quite authoritarian (Landsbergis, 1985). A study of Silicon Valley found electronics assembly work one of five most stressful occupations in the region, along with air traffic controller, intensive care nurse, police officer, and teacher (Global Electronics Information Newsletter 6, January, 1981:4). Most of these are not physically stressing jobs so much as they are positions of great responsibility with very little discretion.
Managers and individuals can use research findings about stress when they plan work activities. The way that work itself is organized can affect physical strain. Workers with more control over their activities report less physical stress. Stress can be reduced by an organization of tasks that do not require continuous keyboard operation. Long sessions at the keyboard can be broken up. Activities that require standing or walking can be interspersed with sitting. In addition to improving productivity, such arrangements can help prevent chronic and permanent muscular and skeletal damage.
Stress also seems to have a temporal dimension. Research on assembly- line workers has shown that people do not like to work with perfectly regular, clock-tick motions. Instead, people like to be able to control the tempo of their own work. When they are able, assembly-line workers prefer to alternate speeding up and slowing down the line. It gives them a feeling of control over their work, and breaks the monotony.
Programs which pace the user at a fixed speed have the same effects as assembly lines; they have been most successful in software designed to help people increase their typing speeds by "driving" them to type faster. Because people have chosen the typing software to improve their own skills, the response time demands are a challenge -- not an imposition. When response time was increased in an on-line computer system at work, employees initially reported higher levels of stress (Turner, 1984).
Although much of the research on computer response time is concerned with speeding up data processing, it seems possible that some patterns of human/machine interaction do not suit human beings. In a study at Ogden, Utah, medical researcher Charles Seizler found rotating shift work associated with cardiovascular, sleep, and digestive disorders. As with jet lag, the people in his study had trouble moving their internal clocks forward. In other words, you have more trouble changing your schedule to get up several hours earlier than usual than you do staying up several hours later.
Since interaction with the computer is often interpreted by the user as "conversation", a slow computer can have a psychological effect similar to waiting for a particularly slow speaker to finish a sentence. As an experiment you can try talking to someone with long pauses between all your words and watch their reaction.
Table 5 lists response times found acceptable to computer users. Notice that acceptable response times for actions that are analogous to manipulating objects are shorter than those for conversation-like interactions (for example, waiting for the computer to answer your question). Recent research by IBM has found user productivity increased by as much as 100% when "conversational" response times are decreased from two seconds to a few tenths of a second. Such findings have been criticized by analysts who warn that we need more and better ergonomic research before we rush out to buy expensive new equipment for the sake of a fractional increase in response time (Lyman, et. al., 1985).
We also need to understand what faster response time means to users. We could, for example, look at the study as showing that higher productivity can be obtained by pushing people to work faster. But faster response time may instead represent a change in the way the user thinks about the human/machine interface. Higher productivity may be obtained by thinking of the computer as a tool that does not require the
Even for adults, LOGO is a rewarding introduction to computer programming. It is as simple as the elementary BASIC language yet contains the recursive procedures and list-processing features of higher-level languages like LISP. The new user gets the immediate satisfaction of seeing the turtle (usually a small triangle on the screen) do just what he or she told it to do. More importantly, after playing with LOGO the beginner has a fairly broad sense of what a computer can do.
For the children, LOGO was an introduction to computers that bestowed a sense of mastery over the machine. For them, the computer is a fascinating toy that does all kinds of things after you give it orders. They learned that they can use a computer to act out an imagined design. The experience also taught them the value of making mistakes. Many of their favorite discoveries were made after giving the turtle a "wrong" command.
A person's experience of interaction with a computer can affect self- esteem in positive ways, for example, a person can be proud of being a good programmer. Computers can also contribute to self-actualization, for example through the satisfaction a programmer gets from making a program LINK COMPUTERS AND SELF-ESTEEM IN CARTOONS work. Or computer experience can have a negative effect on self-worth if the experience makes a person feel incompetent or unfulfilled. For example, people who feel competent and skillful because they are expert typists may feel less satisfied when first learning to use a word processor. Initially, they will be less able to apply their skills to turning out high-quality finished text.
If a person is highly skilled and performs well within an existing organization, new equipment may render his or skills obsolete. This is a threat to job status, and to individual pride and satisfaction. It can also raise real barriers to the successful implementation of computer technology in organizations (Warner, 1984). If the computer is introduced in ways that allow people to preserve their positions and enhance their skills, less "phobia" will result.
User-friendly software can be as much of an affront to human self- esteem as systems that are frustratingly difficult. If "the highest expression of the engineering art is to design a machine that can be operated by an idiot", (Noble, 1980) then how are the operators of that machine to feel a sense of status and accomplishment? One solution is to design "natural" user interfaces in which the machine matches the habits of the people. One example of this as an experimental electronic mail system. Its command language was contructed based upon the words chosen by naive users to accomplish mail searching, reading and deleting (Good, et. al., 1984). Another solution is to provide "training wheels" to make software extremely friendly for new users yet allow experienced users to avoid annoying prompts and menus (Carroll and Carrithers, 1984). New multimedia interfaces are being designed for users at different levels of skill and for those who prefer visual explanations (Thomas, et. al., 1985; "Multimedia...", 1985; Mozeico, 1982). In the experimental APEX system, documentation is by demonstration--the user is shown techniques through computer generated motion pictures (Feiner, 1985). Bolt's conversational interfaces are extremely user-friendly.
FIGURE 11. COMPUTERIZED TAXICAB PRINTOUT
The successful programmer, on the other hand, usually does like to finish projects and see a program actually working. Although the creative professional may put in long hours and spend the last weeks of a project ignoring everything else, the professional lives in a real world with other humans and company deadlines. His or her goal is to accomplish something in the world rather than to live out a fantasy of the grandiose but never- finished computer program. Professional programmers are part of a division of labor. Norms for their roles include communication and coopertion with others (including producing good documentation). While the professional programmer often gets psychological satisfaction from programming, the process itself is not a substitute for living in the social world.
Although many adults view computer hackers as young geniuses, more experienced computer profesionals recognize that, as employees, they are disorganized, difficult to manage, and often incapable of designing or adequately documenting software. When the software industry was beginning, compulsive programmers were often tolerated by companies suffering a shortage of skilled labor. Today, compulsive programmers are less employable. Most companies want reliable men and women who do the work that the company want done. When compulsive-programmer tendencies do crop up in professionals, it is often handled by management as a problem. Some psychologists, like Dr. Steven Berglas, argue that the computer profession does tend to attract rigid, control-oriented personalities. Psychotherapist Craig Brod argues that such "techno-centered" people represent a new type of problem personality. However, psychological tests programmers doing routine work in COBOL found their personalities far from neurotic (Guster, 1985). For even the most creative work, companies have a tendency to insist on real-world relevance.
Some older programmers see the shrinking opportunities for hackers as one sign that programming as a craft is becoming programming as a set of tasks. Many programmers found in the early home computers a satisfying hobby that compenstated them for the progressive fragmentation of their work. Later, when home computers became more common, the attractions for buyers were this challenge of craftmanship, the sense of mastery over technology, and the hacker's escapism. Today, compulsive programming often takes the form of recreation. In leisure activities, escapism and fantasy do not meet with social disapproval, though complaints from families of compulsive home computer owners and from friends of compulsive computer game-players indicate that "computer addiction" is still considered anti-social by many people.
Occasionally, hacking becomes a more serious form of social protest. A U.S. government employee who was officially reprimanded for making what he condidered a legitimate complaint changed the password on a federal data base and then "forgot" it. It had, he said, something to do with the Declaration of Independence. If they would reread that document they might figure it out (New York Times, Feb. 14, 1986).
One difference between the old community of hackers and activities of the newer cracker groups is that the older group had a hacker ethic based on values from a time before much online information was considered to be for-profit property. Hackers shared with the international community of scientists a belief that knowledge and information belongs freely to anyone who can understand it.
Great controversy exists over the extent to which our culturally- defined categories are based on real biological differences between men and women are innate, there is actually very little biological basis for many of these differences. In rare cases, children whose sex was misidentified at birth have been raised to have the traits of the opposite gender. At puberty, with the emergence of physical differences, their status was changed, though their personalities remained more appropriate for the gender in which they were raised. Whatever the real differences are, however, the combination of biology and culture produces divergent behavior patterns between boys and girls. Among these are two directly related to computer use: mathematical competence and desire to achieve mastery.
It is important to remember that the facts that few girls become hackers and most girls seem less interested in computers than boys do not indicate biologically-based differences in ability. It may be that most, or even all, of boys' higher scores on tests of mathematical reasoning and higher achievements in engineering, sports, and other fields emphasizing competition and domination are due to the differences in the way children are raised, and social expectations about their behaviors (Caplan, et. al., 1985; Tobias, 19 ; Fox, 19 ). Also, since many girls have exceptional talents along these lines, the findings do not apply to individuals -- they are differences in the average performance of the two groups. The percentages of women who enter mathematically related occupations (12% of U.S. scientists and engineers) or computer science (30% of 1983 bachelors degrees) are much smaller than can be accounted for by lower test scores. Sociologists point to a complicated combination of subtle social pressures and outright discrimination, and blanket definitions of personalities as cooperative rather than competitive, verbal rather than mathematical, and interested in relating to people rather than to objects.
Women are not encouraged to develop control over objects, nor to engage in fantasies of power. It has been found that female computer science majors are more likely than their male counterparts to drop out of school (Campbell and McCabe, 1984). Some researchers have suggested that this is because adolescent girls are taught to avoid demanding situations, while boys are encouraged to deal with them (Fox, 1977; Wolleat, et. al., 1980). Men tend to dominate conversations, while women are expected to respond supportively and tolerate interruptions (Kollock, et. al., 1985). Even in preschool children, psychologist Malcolm Watson finds differing fantasy patterns. Boys tend to imagine fanciful adventures; girls more realistic and domestic dramas. Within the computer industry women are found, in disproportionate numbers, in jobs like documentation (using verbal skills) or technical support (involving personal interactions with customers). Whether because of discrimination ("women's jobs" in the computer industry are lower-paid) or women's preferences for these types of work, the pattern of female computer use is different from that of males. In both the compulsive world of hackers and the more ordinary world of industry, computer power is more often sought and obtained by men.
As computerization expands, such differences may decrease. There has been a trend towards less sex-role stereotyping in U.S. children's books (Kinman and Henderson, 1985). If the computer comes to be viewed as a general-purpose tool applicable to a wide variety of tasks, instead of a mysterious piece of "high technology" over which to obtain mastery, the psychology that confines computers to the male sphere of activity may diminish. Already office automation is producing computer systems designed specifically for a female clerical staff. Micro-computer manufacturers are trying to sell the idea of the computer as a household appliance. Also, women with mathematical talent and an interest in technology are increasingly ignoring traditional social definitions of what they are "supposed to" want to do. A 1985 study of California high school stuents found no differences in male and female attitudes towards computers (Fisher and Pulos, 1985).
When I first used an automatic teller machine I thought about the jobs of tellers. I wondered if anyone were put out of work by my actions, and in what ways the work would change. My brother-in-law eventually married the teller who cashed his paycheck every Friday--the opportunities for that sort of social interaction might be reduced. Yet I had observed bank customers arguing with tellers and being generally unpleasant, so maybe the loss of social interaction on the job would bring improvements as well as lost opportunities. Then there was the awkward business of following the simple instructions for entering my card and code numbers while people waited in line and I felt slow and incompetent. Was this really a better way to get money out of a bank? Today the card goes in the slot and the numbers are punched without conscious thought. I use the teller machine by reflex; jobs for bank tellers declined by a third. Reflecting on the small nagging guilt at having contributed to the loss of someone's job is part of why I wrote the paper version this book. The web version grew out my experiments with students and colleagues to try to do something about the computer revolution's impact on our own situation.
Individuals experience the computer revolution as a series of minor changes in the world. Each small change is confronted as a temporary disruption in our comfortable patterns. Unless we reflect on our negative experiences with technology, they are soon forgotten or rationalized as part of our inevitably changing society. We adapt to change, alter our habits, and carry on. Unless we are caught up in the popular enthusiasm for the computer (or unless our jobs are eliminated or altered), most of us will notice very little change from day to day. Only when we pause to think over the experiences of our lifetimes, or when we listen to the accounts of older acquaintances, do we see the intersection of biography and history, and realize that we and our culture are changing.