For some time now, some researchers in the field of the human sciences have taken to dissenting from the purely empirical, «quantitative» position. Since reality is no unidimensional phenomenon - the main argument of some researchers - it does not make sense to rely strictly on quantitative methods. This other school advocates combinding quantitative and qualitative methods. But, warning from the aspect of methodology: it must be emphasized that reliability of the data is crucial. Only if data gained by qualitative methods are sufficiently reliable the combination of qualitative and quantitative methods can be recommended. This fundamental attitude toward applying quantitative in combination with qualitative methods is not only characteristic of this volume, it served as the decisive criterion for the selection of the contributions included.