QDUAL examines the current process of quality assurance and development in dual study programs in Germany. The process tales place between the poles of different institutional and actor-related interests as well as against the background of divergent concepts of quality. Research on this topic is important because the hybrid qualification format has experienced rapid quantitative growth over the past ten years and is becoming more differentiated. However, student and graduate surveys provide evidence that the expected good theory-practice-link, the conception of the practical phases as well as the learning support and documentation of the qualification in the companies could be improved in some places. The project aims at new and more data-based insights into the interplay in which structural and organizational as well as subject- and industry-specific factors influence quality assurance in dual study programs. For this purpose, an integrated multidimensional and multi-perspective mixed-methods-design is used, which is based on the combination of various qualitative and quantitative techniques of data collection and data analysis to define more precisely the degree of coherence between formal requirements and regulations concerning the quality assurance of dual study programs on the one hand and subjective theories and practices of the actors involved on the other. Major goals are a) to identify problem areas of quality assurance and b) to find "best practice solutions" for quality assurance and development and scientifically reflect on them. Based on project results, a transfer of knowledge is planned to universities, universities of advanced studies, and universities of cooperative education as well as the related companies, regional umbrella brands of dual study programs, chambers (IHK and HK), and educational policy-makers.