The use of digital media by children and young people offers opportunities for communication, collaboration, and participation. However, to prepare them for the risks and challenges of media usage, promoting digital competencies of students and teachers is an indispensable goal for educational institutions. To meet this requirement, teacher education must be opened to innovative pedagogical concepts for initial teacher education that considers new technologies in a reflective, action-oriented way to promote competencies. Therefore, this work aims to promote the technological pedagogical content knowledge (TPACK) of prospective teachers that enables the purposeful integration of social virtual reality (social VR) into the classroom. Consequently, a pedagogical concept is developed and evaluated in an iterative research and development process following the design- based research approach (DBR) through four consecutive studies. The first study involved an analysis of the requirements of teachers and students for the effective use of social VR in the classroom. The second study examined how prospective teachers perceive teaching and learning activities within two theory-driven scenarios in social VR. The third study investigated the development of Technological Pedagogical Content Knowledge (TPACK) among students in social VR compared to video-based communication. Finally, the fourth study measured the development of TPACK in social VR using epistemic network analysis, finding that social VR can be an effective tool for teacher education, emphasizing the importance of authentic contexts and practical experiences for effective teaching in social VR. In the concluding chapter, appropriate implications for teacher education research and practice are derived from findings. For example, that a deeper understanding of TPACK as metacognitive awareness could enhance teacher education for media integration. It also highlights the need for digital literacy in seminars that address new technologies, emphasizing the importance of considering moral values and sustainability when using VR.

Media have become omnipresent in children’s and youths’ everyday lives, and they also offer rich chances and challenges for educational contexts. On the one hand, media can, for example, support students’ learning effectively, enhance lessons with innovative tools and methods and help individualize teaching and learning processes. On the other hand, students need to learn, e.g., how to use these media, how to select and evaluate them and how to act responsibly in a digitalized and mediatized world. Teachers are a core stakeholder in this context. To take advantage of the benefits media offer for teaching and learning processes, to support students in the acquisition of respective competencies and to fulfill numerous other media-related tasks and challenges, teachers need to acquire respective competencies in their initial teacher education, which can be summarized as media-related educational competencies. The relevance of these competencies is evident on different levels. In related research, respective competency models are developed, and in practices of teacher education, competencies are measured and efforts are taken to advance the competencies of preservice teachers. Against this background, this semi-cumulative dissertation presents a theory-based and empirical analysis of the competencies in question from a comprehensive and multidimensional perspective. In accordance with the central aspects outlined, the three systematic main fields focused on are models of media-related educational competencies, their measurement and practices of advancement in teacher education, as well as the interplay of these three fields. The dissertation takes on an international comparative perspective and focuses on the examples of initial teacher education in Germany and the USA. The article-based dissertation comprises three main parts, framed by introduction and conclusion. The introduction provides a basis for the following work with regards to terminology, scope of research and overall methodology. The first main part is concerned with models of media-related educational competencies and includes a theory-based systematic comparison of three relevant models. This part explicates the varieties between competency models, and it discusses central aspects of selection and application. In Part II, methods and varieties of competency measurement are focused on, and an article is presented which shares results of an exploratory quantitative measurement of the respective competencies of German and US preservice teachers. Overall, this part reveals the potential and limitations of competency measurement and transfers these conclusions to the competency models introduced in Part I. Part III is concerned with an analysis of current practices of advancing media-related educational competencies in Germany and the USA. In this context, stakeholders influencing these practices will be systemized and analyzed in their role and impact. The article included in Part III introduces interviews which were conducted to achieve insights into the perspectives of selected experts, regarding relevant models, practices and outcomes of media-related teacher education in Germany and the USA. Finally, the Conclusion of the dissertation will draw together the different strands, clarify the close connection between the domains of modeling, measuring and advancing the competencies in question and discuss the interdependencies of these three dimensions. These perspectives help both to contextualize and bring together important facets which have often been treated separately in related research and will add new facets to ultimately achieve a comprehensive and multifaceted viewpoint. Against the background of the intercultural comparative perspective, the results and findings will ultimately achieve an enhanced and deep analysis and reflection on the complex field of media-related educational competencies in Germany and the USA and beyond.