In the context of research methodological triangulation and in alignment with mixed-model designs, there has been an increasing number of studies in empirical educational research in recent years that combine qualitative and quantitative instruments and analyses as part of a unified research approach. Against this backdrop, central methodological questions and a variety of empirical studies were presented and discussed during the 74th conference of the Working Group for Empirical Educational Research in 2010 in Jena. This volume engages with this discussion and provides an exemplary overview from the foundational and perspective aspects of research methodology to concrete application examples from empirical school and teaching research as well as teacher education research.