Publication history, Reflections & comments
ERGONOMICS is the applied science of people at work. Traditionally applied to factory tasks, it must now be applied to how information is handled in the modern computerised workplace.
The term was introduced by Ken Murrell in 1949 and was derived from two Greek words: "ergon" meaning work and "nomos", knowledge or foundation.
Murrell had worked with a multi-disciplinary team at Cambridge tiniversity during World War U on the tlr gn of weapons systems to suit humans.
With the end of the war, this group stayed together to form the Ergonomics Research Society, the forerunner of similar organisations to be found in practically all countries today.
They Ergonomics Society of Australia was founded in 1963. Following trade union activity in 1981 ergonomics– also known as "human factons” became part of a general strategy in occupational health and safety, with great attention placed on the needs of workers in general for properly designed equipment, work layout, environment and systems.
The rapid growth of word processing and other computer applications focused attention on these areas.
Workers and unions became acutely aware of desks or chairs at the wrong height, screen glare due to bad lighting, aching and discomfort at work, and concern about radiation damaging unborn children or causing cataracts of the eyes.
There was a flood of information On such matters, much: of it inaccurate. Only now are clearer views appearing of the RS1 epidemic of the 1980s.
Unfortunately ft is likely that much of the important potential of ergonomics. for improving productivity and quality of work life. will be discredited in the short term because of the exaggerated problems and claims invoked in its name.
It is therefore important to clarify those areas to which ergonomics can make a legitimate contribution:
Ergonomics is far more than and keyboards. In factories it applies to:
fine assembly work, such as circuit boards, where studies of hand grip can lead to better instrument.design and better methods of handling
lifting, since back injuries are those the most common and expensive type of injury, and
- information handling.
Because ergonomics is based on normal human capacity and how it relates to work, it requires a basic knowledge of anatomy, physiology, psychology and engineering, combined in a systems approach.
The concept of "system" is worth more than a passing mention. Despite the work of mental giants like Gerald Weinberg (general systems theory) and Ludwig von Bertalanffy (author of "Problems of Life'), it still seems worth presenting systems through metaphor.
A system is a set of items, each with structure, content, energy and information, which affect one another, sometimes to an extraordinary degree. A mechanical analogy is a mobile suspended from the ceiling of a child's bedroom.
Move it at one end, and other parts begin to jiggle in various ways. Move it a little harder, and the lot may come tumbling down — collapse of system.
|Technical systems -- rarely as simple as the motor car|
Gerald Hofstadter refers to emergent properties. Knowing the properties of individual items in a system, and they relate to each other one at a time, does not help in understanding the behaviour of complex systems, especially if they are unstable ones.
The philosophy of causation in industrial accidents today is concerned with the difference between those systems which are tightly coupled and those which are loosely coupled, to use the 1984 terminology of Charles Farrow in his book Normal Accidents.
Unfortunately it is likely that much of the potential of ergonomics for improving productivity and quality of work will be discredited in the short term because of the exaggerated problems and claims invoked its name.
How many engineers predicted Three Mile Island, or Bhopal, or Chernobyl, or, many other recent events in the, human drama? How many computer programmers would have expected the violent reaction to the introduction of word processors, or their failure to increase productivity significantly?
The challenge to programmers and system designers is to make their systems so natural to use that they are invisible to the user. The user then thinks of the task' or goal and not of the mechanism or means.
"Point and press" applies not only to a mouse but to a motor car – you point the steering wheel and press the accelerator pedal or the brake.
Training, experience and natural aptitudes count for a lot. However, technical systems are rarely as simple as a motor car.
There are many other analogies between different systems which involve interaction between humans and machines.
The basis for effective use in each case depends on a range of factors, some of them hardware design, some of them design of information, and some of them, among the most subtle, human factors – personal, psychological, behavioural. You can't always be clever but you can often be kind, and this makes a big difference in many organisations.
Software ergonomics, or human computer interaction, is concerned with such, matters as screen format, documentation, the mental models of system design that users have, and training. Good interface design helps avoid confusion and dissatisfaction on the part of users. Such design is based on cognitive psychology; in terms of normal memory and schemas or mental models.
Guru James Martin expressed the problem in his typical. crisp style:
"When end users communicate with a terminal, the structure of the dialogue they employ is very important.”
"Computer manufacturers employ ‘human factors' experts. But most of the time they are concerned with such factors as the feel of the key-board, the position of the switches and the glare of the screen.
"Much more important is the structure of the dialogue.”
"What does the machine say to the user? Can he understand it? Is by confused by any part of it? Does he know how to respond or how to initiate an interchange?"
Referring to complex signing-on procedures, Martin says:
"Perhaps this is fine for technicians and university. professors, but the computer industry now has to ' lure all mariner of reluctant users to sit down at terminals.”
A complex sign-on procedure will make them stay away in droves, he says.
"With some. terminals it is almost equally difficult to sign off."
For the human-computer system to function at its best, the capacities and limitations of each of the two components must be recognized.
Humans can think quickly about new abstract ideas, and can call to mind a huge reservoir of thoughts and experiences from their life.
Compared with the average human, machines have access to only a small collection of data, which must be made accessible to them.
Humans can fill gaps in language and understand poor. grammar, though usually language has a great deal of redundancy. Machines require precise syntax, but are very fast and exact.
A simple example of the differences between humans and machines is asking someone to recite the names of the months of the year, but in alphabetical order.
Such a re-arrangement is very difficult for the human, but is undertaken by a suitably programmed machine in less than a blink.
Humans in Europe will associate December with Christmas and snow. Computers will only do this if a special separate effort has been made to make this Information available.
Habit is more important than logic. The student, or beginner, may be strongly equipped with rules, or tools of logic, but what makes it easy to solve a problem is having solved it. before, or one quite similar to it.
To the non-computerist it is difficult to think of new expressions. like logon, root directory, file numeric field and buffer.
A major barrier to the wider use of technology is that clever technicians and professionals forget the problems that ordinary people of different training and intelligence have in understanding how to use technology, while it is not presented hi the familiar terms of the language they use for their own activities. Even worse, many technologists cannot write clearly when they use everyday language.
In the next in this thought-provoking series, Michael Patkin talks about the post-information society, the limits of short-term memory and working memory, and the nature of natural and written language.
THE Australian Tuesday October 20 1887 COMPUTERS and High Technology
Limits are set by users, not machines.
|In the second of a two-part series, Australian Computer Society lecturer of the year, surgeon MICHAEL PATKIN, concludes his address to computer professionals on ergonomics in today's user society|
We are past the fifth industrial revolution, and no Ionger in the information society. We are in the post-information or "user society.”
The potential and limits of computersystems are no longer set by machine cost and machine memory, but by the cost, capacity and limitations of the users of systems.
In plain terms of dollars and cents, efficient design of the user interface is important for four main reasons — the cost of training and re-training, productivity, error rates , and user satisfaction.
The human basis for software ergenomics lies in psychology, in the study of human learning and human memory, and in human capacity for taking in information, especially printed text and other symbols, but also through, other senses such as hearing.
Today's personal computers with 640K memory have rapid access to the equivalent of 250 pages of single-spaced text. A normal human being can only remember six or seven things at a time, and is likely to make a mistake even then, especially if distracted.
These remembered things may be simple ones like digits, or symbols, or they may be chunks, each of which is a complicated concept such as breakfast, or slipping on a banana, or toothache.
The function of training or experience is to aggregate separate items into larger ones.
To phone New York, for example, means dialing (or keying) 0011 for international, 1 for North America, 212 for New York State, and then a further seven digits for the individual telephone number.
The sequence of 00111212 becomes one chunk instead of eight digits or three shorter chunks. Habit is more important than logic in using this data reliably.
Life is short, and few people have the time to learn MS-DOS or Unix or Pascal. They rely on others to put this detailed technology into a shape which is usable for them. I am not able to take apart the carburettor or the engine on my car, but I use a car several times a day to carry me from one place to another.
If I go to the kitchen, it is not to use hydraulic and thermal systems with reservoirs, conduits, controls, energy supplies and materials, but to make a cup of tea to drink. Yet today's computers, even the friendliest, are a headache to use for most people, even for experts.
The Apple Macintosh, child of Lisa and grandchild of Xerox Star at Palo Alto, still takes a normal person three days to get to use well, not just half an hour. Other systems, are much harder. Humans handle natural language best.
Language is natural when it is used easily and clearly: on the basis of familiarity and does not require the intervention of conscious analysis. A family's cat has no problem in "asking" to be let out the door.Other examples of natural language are:
A CHILD of five years old in Paris speaking simple everyday French, perhaps also shrugging his shoulders, elevating his eyebrows, extending his upturned hands, and saying "Je ne sais pas" to indicate he doesn't know;
A SURGEON discussing choledochoduodenostomy among a group of other surgeons, or writing about it in a specialist journal;
A FAN of horse-racing listening to a radio broadcast of race results, spoken rapidly by the announcer;
A SCIENTIST used to working with statistical data, reading or constructing chi-squared correlations.
The inability of some engineers and other professionals to write clearly is notorious and an expensive handicap to their readers.
The writing of clear documentation is important for many practical reasons, including whether a package will sell well,' or whether users will have problems and need frequent help from their supervisor or from the programmer.
The ergonomics of text can be considered under several headings: legibility, layout, language, sentences, paragraphs, page and book design. These considerations become even more important with the wide use of desktop publishing, because the normal constraints on bad writing (such as an editor) will not apply.
Such technology, like the use of fire and other, powerful human inventions, is a good servant and a bad master. There is an opportunity to improve documentation enormously, and to make big mistakes.
Such mistakes will include illegible print-outs, too many typefaces (or illegible ones such as Gothic), solid slabs of upper-case letters, poor spacing, jargon, incomprehensible sentences, poorly defined paragraphs, amateurish pagination, glossy paper on which ink runs, and booklets which require one pair of hands to hold open as well as an-other for the keyboard.
Experience is that such mistakes are ignored.
Rules for good writing should be part of the stock-in-trade of any professional. These rules are the subject of several excellent books, such as Flesch and Gowers.
|Technologists are notoriously unable to write properly|
Here one merely recalls in dense unfriendly text the need to:
USE short familiar words;
KEEP to the active rather than the passive voice;
AVOID negatives, especially double negatives; .
PUT "not" instead of an apostrophe (don't), or a prefix ("not edible" instead of "inedible");
MAKE sentences short and cut paragraphs thin, like salami, to make them digestible;
REVISE and rewrite. Word processors eliminate excuses for this. Edit for format, style, language, substance and context;
BREAK these rules at the right time.
Screen format is the subject for textbooks rather than a few sentences. In a large organisation, good screen design is worth a lot of money.
One study by Bell Telephone in the United States showed that 0.8 seconds saved from each telephone directory inquiry would save labour costs of $40 million per year.
The common mistakes made in commercial software packages are inconsistency, strange or confusing language, error messages which are obscure or frightening, poor use of colour, and heavy demands on short term memory which lead to error.
Screen format can be improved by incorporating interface standards as part of the initial design brief, separating the software for the user interface from other parts of the pro-gram, presenting less information per screen, matching the layout of captions and data entry fields to that of source documents and by testing usability on groups of typical users before considering the design complete. .
Programmers unfamiliar with Shneiderman's book, Designing the User Interface may well find them-selves at the receiving end of complaints or lawsuits for incompetent design in the next few years.
Ergonomics has a special double significance for a country like Australia. .
It can contribute to a better quality of work life, by decreasing disability and increasing satisfaction and productivity in work.
It can also contribute to better design of manufactured products which can then compete more successfully on the international marketplace, perhaps creating a style as distinctive in its own way as that of Scandinavia, or other cultures.
The past four years have seen a rapid increase in the use of the term ergonomic in describing articles that have won awards from the Industrial Design Council of Australia, including prizes for software. Apart from the .world-wide growth of interest in human-computer interfaces, there are special reasons that development will be strong in this field in Australia.
Noted overseas experts such as Shneiderman, Galitz, Brockman, Shackel and others have visited.
The activities of Australians such as McKilliam, Lindgaard, Morrison, Douglas, Seeley are increasing; and there are obvious commercial advantages to be found in the development of Australian software with a well-designed user interface.
Trade union interest, too, is shifting from the area of physical strain to that of mental workload. From past experience, the rest of the Australian community had better get its house in order, to prevent expensive and avoidable confrontations.
Finally, maturing attitudes throughout our society - are able to accept . a hierarchy which goes beyond that of data / information / knowledge / wisdom to higher human aspirations and feelings.
Just as organisations now look beyond aims, policies, strategies, procedures and practices to values, beliefs and trust so technology becomes more the servant of humans and less their master.
This was a two-part series in The Australian section on Computers and High Technologyr on Tuesday October 13 and 20 1987
The Australian Computer Society's lecturer of the year.
Surgeon MICHAEL PATKIN spent 1987 engaging computer professionals in the debate on ergonomic issues.