Limitations
There are some limitations of our study to be considered. As mentioned above, the fact that we conducted our study before the COVID-19 pandemic can be seen as both a disadvantage and an advantage. Although our intervention aimed at collaborative, not contextual learning, we did not analyse the PbL process itself, tutor behaviour, or the learning goals derived from group discussions. This should be addressed in future studies. One should be very careful with interpreting findings from qualitative analyses in a (semi-) quantitative manner. Therefore, we have of course only described these results and not analysed them statistically. The results of a single-choice exam only partially reflect the learning success in PbL (Davis and Harden 