[Exploratory and confirmatory factor analysis]

This article describes the utility of factor analysis in the context of developing questionnaires for clinical use in rehabilitation. The basic principles of both exploratory factor analysis and confirmatory factor analysis are presented in order to give the necessary knowledge for choosing between both concepts. Exploratory and confirmatory factor analyses complement one another, and there is a place for both in the process of questionnaire development. Finally, the potential use of factor analysis for scaling procedures as well as intercultural validity studies is outlined.