To understand or not to understand? Evidence and challenges in assessing the potential of Problem-Based Learning (PBL)

With problem-based learning (PBL) now a widely advocated instructional approach in higher educa- tion, empirical evidence about PBL’s potential to foster student learning is crucial. The present paper presents results from a research project funded by the German Federal Ministry of Education and Research (BMBF). This project followed the objective to give recommendations on whether PBL should be advocated for German higher education on a broader basis. The study compares students following a PBL curriculum to those in a traditional lecture-based curriculum to assess whether the former acquire deeper and more complex knowledge structures. In the sense of Schaper (2014), this study can serve an example for effectiveness research (Wirkungsforschung) focused on the course- concept instructional level. The experiences gained within our approach illustrate the specific chal- lenges of this type of research, especially when conducted in a non-experimental field and with non- randomized samples. The findings shed light on a potential measure of learning success in PBL curric- ula, and on possible advancements in research designs for (higher) educational purposes. Our paper can serve both as an example and as a starting point for further research, addressing not only research into the efficacy of specific instructional arrangements, but also the complex interplays between research questions, designs, measures and obtained empirical evidence.