Summary Integration, not confrontation! On the methodological discussion about the respectve values of quantitative und qualitative research Although the combination of qualitative and quantitative methods is widely employed by research practitioners in the social sciences, the well established schism between the two research traditions still frequently emerges in methodological debates. While many authors in the educational sciences pretend that only a standardized and statistically oriented methodology is able to deal with the relevant questions in this field, others propagate qualitative methods as the only appropriate approach to the specific problems of this research field. This article contradicts both views and goes on to show that especially those research programmes centred on developmental processes can benefit from an integration of both perspectives. Associated with this research strategy is the problem of the methodological foundations of the different techniques. Instead of developing alternative methodological deliberations for the qualitative research, a common methodology for scientific research in general is postulated. Starting from practical experiences with biographical and life-course research, the strengths and weaknesses of each approach are contrasted with one another. The benefits of their combination are then considered. A multi-method approach leads to an improvement in the validity of conclusions drawn out of research findings. The utilization of different methods — which are often grounded in different paradigms — sheds light on the problem that research findings often show different phenomena and not the different aspects of one phenomenon. The discussion of the relationship of the findings to one another (congruent, complementary or divergent) shows that another strength of this multi-method approach lies in the empirically induced modification of existing models and theories, as well as in the development of new explanations.