[Making a surgical decision: interplay between experience and clinical study].

Although the final, individual decision making in patients always has to be in the hand of the doctor, it has hitherto been much less a matter of scientific analysis than formal decision making on the basis of clinical trials. To change this, several types of individual decision making were characterized, four in the field of intuition (very fast logical decisions, consciously and unconsciously heuristic decisions using special instruments, the deep remainder of intuition which can and should not be the subject of scientific analysis) and discursive (purely logical) decision making as a fifth type. The prospective think-aloud technique including an hierarchical heuristic decision tree was presented as a method for scientific analysis of individual decision making which is open to repetition and criticism. The place of various types of formal trials in this process was defined. Via a posit and the heuristic instrument of representativeness, the problem of the transfer of results from clinical trials to the individual patient was solved.