ABSTRACT
In all sectors of our society a growing complexity can be witnessed. We are using more and more complex machines for 'making our life easier'. We don't travel any more by horse but by car, and not by stage-coach but by train or aeroplane. We don't need to collect and burn wood or coal for heating meals any more, but are now able to do the same job in seconds by means of a microwave. We don't use typewriters any longer, but we use computers with 'word processing programs'. And these computer programs become more complex over the years, integrating more and more functions. In order to make sure that ordinary people can handle them, computer programs, cars and other complex machines are being designed in such a way that their operation is very simple. Much attention is devoted to the prevention of undesirable situations, i.e. a 'perfect' machine or computer program should be foolproof. The ultimate aim is that full operation is possible by just pressing a few buttons and that nothing can go wrong if the wrong buttons are being pressed. Evidently, the growing complexity of society seems to go in hand with a growing need for simplicity and survey ability.
