[Helping physicians arrive at medical diagnoses: how and why (author's transl)].

In the majority of the medical disciplines the diagnosis still constitutes the corner-stone of medicine. Every year this function becomes increasingly difficult and time-consuming and it is felt that the doctor should be able to benefit easily and rapidly from the most recent findings. A simple analysis of the natural process of decision-making, followed by a critical inventory of the various methods used to diagnose, has led us to develop our method for computer-assisted diagnosis (ADM). In our presentation of the methodology of diagnostic decision-making we examine the natural process, the analytical and synthetic methods as well as the difficulties and errors liable to occur. Four methods used in arriving at a diagnosis are analysed and criticized: those based on probability, those based on pattern recognition, those based on logic, and those based on classification methods. Finally a case is made for a computer-assisted diagnostic system based on a logical method of the documentation type.