RESUMO
One of the common features of the five Public Health Research Centres of Germany lies in quality assurance and quality improvement of their research activities. The institutionalisation of systems of quality improvement of Public Health Research has to be regarded as innovative, hitherto unparalleled, in the German context. The article deals with the demands on quality improvement confronting empirical research, the possibilities of coming to terms with this challenge, and still unresolved problems of implementation. Demands will be outlined in discussing quality criteria and processes of empirical research, paying special attention to differences between qualitative and quantitative designs of inquiry. The concept of quality improvement, developed in the Munich Public Health Research Centre, applies two basic strategies to meet these demands: enhancement of the transparency of the research process, and the training of research staff. Instruments for quality improvement are introduced: some of them may be applied by the research team itself (such as study protocol, research diary, team discussion) some of them have to be realised by external staff, especially responsible for the process of quality improvement, in cooperation with the research team (quality circles, training, compilation of written material). In conclusion, the implementation of instruments of this kind is discussed, concentrating on the problematic cooperation between research team and external staff.