Abstract
The methodology of clinical research will be commented upon according to the components of the research design: a precise question, hypotheses derived from that which can be examined empirically, the biometrical estimation of the sample size and its practicability, the selection of control groups, measures for assessing psychopathological phenomena, analysing the data and preparing the findings for publication, further the time structure of the research project, and some aspects of the framework of clinical research: patient access, financing of the needed resources and ethical implications.