Very important is also what is on your screen.... Avoid a cluttered desktop. If you have to look all the time all over the screen to find what you need is very tiring.
The Ergonomics of Graphical User Interfaces revealed
Sometimes it can happen that a group of people accepts a basic concept on a false premise, and from that basic concept they evolve a complete belief system, surreal in its nature but thoroughly convincing in its logic. In the course of the world's history we have seen, mostly to our detriment, the consequences of such blindly following the path of logic.
Such a situation seems to be happening concerning the total acceptation of the Graphical User Interface, or GUI for short, as a valid ergonomical solution to computer use. What is this basic concept? Well that is a rather long story, too long to fully discuss here but in its essentials it goes something like this:
Mankind is mostly visually oriented. He appraises his position in the world based for the largest part on visual stimuli, supported by the other senses. So one smart kid some while back thought, if mankind is visually oriented then his interaction with the computer should also be visually oriented so to best fit with his natural inclinations.
Also the visual cortex of the human brain is very highly developed, with an enormous visual memory capacity. It all stands to reason then, let's make an computer interface mainly based on visual entities, graphical representations of the functions man wants his computer to execute.
This is the basic premise of the Graphical User Interface. So what's wrong with this premise? Well several things are wrong with it; let's start from the input of the visual information: the eye.
The human eye has a natural resting point which puts its focus at a few yards in front of the eye, which we inherited from the old days when man was a hunter/gatherer and mostly focused in the distance. In order to focus close by the muscles controlling the lens need to be constantly active so looking intensely at a computer screen puts enormous strain on the eye.
The next problem we encounter is that of color images. The eye is best fitted for black/white perception, that is black/white contrast. Because when trying to differentiate between the contrasts, black/white contrast requires the least amount of energy level differences for the eye to react. Apart from the biological reasons (the retina of the eye reacts to white light stronger then to colored light) it is simple physics which demonstrates that the difference between no photons coming in (black) and photons of almost all visible frequencies all at once coming in (white light) is a much stronger stimulus then differences between photons of the separate frequencies of color.
So the eye has an easier job seeing black background/white foreground then color/color or even black/color. Because the difference between energy levels of black/white can be so small, obviously since seeing the difference between no light and some light is easy, the image presented to the eye in black/white needs less contrast. Which in its turn is more restful to the eye. In short, color images are less ergonomical then black/white images.
In order for the brain to correctly recognize pictures or forms it needs to scan them at an intense rate, so to give the pattern recognition modules of the brain the chance to make heads or tails of it. This is a very complex and energy consuming process, since the brain dissolves the picture in distinct angles of lines to make a sample for the recognition modules. Having finally recognized the picture as an picture, it then needs to link the visual information to the (let's call it) main memory banks of the brain to elicit a response to the picture. Then in order to make the picture aware to us, the language interpretation module needs to link it to the words describing the picture so we can form the conscious description of the picture.
All in all in a very lengthy, complex and extremely energy hungry process, just to be able to interact with a computer, so in its basic concept directly opposed to the principles of ergonomics.
A more efficient way is to offer the brain letters, which get recognized more easily, as they are less random in their patterns. Furthermore, the letters themselves directly elicit a response from the language interpretation module, thus cutting out the whole lengthy route of visual interpretation, thereby saving a lot of energy and as such very much in touch with ergonomical use of the brains resources.
Then we come to the windows concept of GUI's. It is a simple fact that the more cluttered a picture, the harder it is to find that part you're interested in. The best way to present data, is to present only that information which at that point in time is what you need. Pretty looking windows, with action lines filled with nice little colored pictures, making no real sense in themselves is about the most un-ergonomical way of presenting data one could possibly imagine.
Then we get to the next point in question, the pointing device. A must for a GUI, with it's basically random access method. For discussions sake we'll concentrate on the mouse, most often used as a means to access the GUI. Mouse movements require an enormous amount of brain power, as the hand/eye coordination is one of the most difficult processes the brain can be burdened with.
Not only does the brain constantly has to update the visual information of the target, it also has to calculate the movement of the hand controlling the mouse. This also is directly opposed to the principles of ergonomics. A more efficient way is using key sequences, such alt-f1 or crtl-f2. These movements are not random, but always the same (on the same keyboard obviously) Therefore they get hardcoded into the brainstem, where all other repeatable movements are stored as distinct neural patterns. Walking, driving a car, swimming all are stored there.
This has the big advantage that the brain needs not be conscious of the actual process of moving the hand, it just needs to activate the correct pattern and let the pattern run its course. This is an enormous energy saver and as such is also very much in touch with ergonomical use of the brains resources.
Summing up the best possible way of presenting data to a human:
A black background with a white foreground, with the least possible contrast, only letters and numbers, with the least possible amount of irrelevant data onscreen and a keyboard controlled input.
What is a GUI?
A colorful image with lots of contrasts, pictures letters and numbers mixed, with an enormous amount of irrelevant data onscreen with an mix of mouse and keyboard controlled input. Where does all this leads us to? Well, not to immediately dump all GUI's. There are a number of special circumstances where a GUI does offer distinct advantages over a character based interface. However it is advisable to first look at the task you want the computer to do for you, and on that basis decide which interface will best suit your needs. One thing is clear though, when an application is in itself character oriented, such as for example most forms of data-entry and word-processing, then a character based interface will be the best choice. This being about 70% of corporate computer use, the current trend in corporate computing towards GUI's is somewhat ill advised and will in the end lead to diminished returns on their investments.
And what's even more important, will cause the regular user unnessecary strain when using the computer and cause a higher instance of sick leave. Much has been said recently about Video stress, theories abound on the causes of such an infliction, from ELF radiation to bad seating arrangements. It can be easily demonstrated however, just by the enormous amount of different symptoms, that video stress is a composed affliction, combining the effects of bad seating arrangements, overhead lighting with fluorescent lights, a badly designed user interface and irritating software, and monotonous work.
Nowadays much attention gets put into diminishing the effects of most of those factors,
( for example in the Netherlands just recently a law was passed which makes it illegal to work more than two hours at time with a Video Display Unit. This obviously misses the point, since it is not the Video Display Unit which causes stress but what is (and how it is) displayed on it. Research has shown most radiation (if any) extends towards the sides and back of a VDU, so the safest place is right in front of it. But at least it diminishes the time spent getting frustrated by the software so it should help somewhat.)
but it is rather strange to see that exactly the opposite gets done int he case of the user interface by introducing GUI's on the workplace! In conclusion one could say the age old error gets made all over again, where we confuse sensual satisfaction (pretty pictures) with what is good for us. As in alcohol and other drugs the gratification gained by this sensual stimulation can't be held against the detrimental effects. This process also can be brought back to brain function whereby the limbic system, which controls amongst other functions our emotions, takes over and controls our thinking processes to such a degree we can't decide on a rational basis but just on an emotional basis.
Which would be just fine if you want to fall in love, but is somewhat less helpful if you want to make a decision which influences your daily work. What's even more unfortunate however, is that the link between harmfull effect and chemical substances is easily proven, but in the case of video stress will be somewhat harder to do. Which makes that we'll all have to suffer headaches, being tired every day, lack of concentration, not being as fast in our reactions, diminished tolerance of mental pressures, irritability, disturbed sleep, pains in back and neck, rapidly diminishing eyesight, mood changes and most other vague but none the less disturbing psychosomatic complaints for some time to come yet .For those interested included is this short literature listing, which covers most points discussed here:
M.S. Gazangia, The social Brain,D.C. Dennet, Brainstorms,J.A. Fodor, The modularity of the mind,A.D. Baddely, The psychology of memory,R.W. Brown, Phonetic symbolism in natural languages,T.N. Cornsweet, Visual Perception,P. Davies, An effective paradigm for conditioning visual perception,W.N. Dember, Psychology of perception,N.F. Dixon, Subliminal perception,J.J. Gibson, The ecological approach to visual perception,P Geert, Transparent self-reference and the structure of perceptual awareness,L.M. Hurvich, An opponent process theory of color vision,P.D. Maclean, The limbic system in relation to central gray and reticulum of the brain stem,F. Jacob, The possible and the actual,S.E Micheals, QWERTY versus alphabetical keyboards as a function of typing skills,P Vroon, The tears of the crocodile.