Means like menu-techniques or so called help-files for simplifying the handling of various appliances have gained a firm footing in most fields of professional or semi-professional technology. Evidently this trend will extend even to the smallest microprocessor equipped professional device. Only in the field of consumer electronics, where even a timer controlled video cassette recorder has proven to be a technically very complicated machine, no realy drastic progress is visible. Instead extremely difficult to handle appliances which require large instruction manuals are still developed and marketed. Here a large number of switches and buttons dominate, though an intelligent application of the principles of "user-guidance" already known today would allow simple and self-explanatory control units.