This paper is an attempt to discuss the principles of confirmatory factor analysis in a fairly simple way and without recourse to mathematical techniques which are either difficult or not well-known among German social scientists. Merely knowledge of the fundamentals of path analysis as well as of classical or exploratory factor analysis is taken for granted. Beside first-order factors, second-order factors are introduced. Assumptions and characteristics of confirmatory and exploratory factor analysis are compared with each other. The comparison does not focus on mathematical details but on „psychology“ and practice of research as well as on substantial or theoretical utility of both approaches. Use of confirmatory factor analysis is especially recommended, if there are multiple, but defective indicators for each theoretically important variable, firstly in order to test the assumption of merely random or unsystematic measurement error, secondly in order to eleminate the effects of such errors by moving from the indicator to the factor level of analysis in testing substantial propositions.