The amount of research on virtual reality learning tools increases with time. Despite the diverse environments and theoretical foundations, enough data have been accumulated in recent years to provide a systematic review of the methods used. We pose ten questions concerning the methodological aspects of these studies. We performed a search in three databases according to the PRISMA guidelines and evaluated several characteristics, with particular emphasis on researchers' methodological decisions. We found an increase over time in the number of studies on the effectiveness of VR-based learning. We also identified shortcomings related to how the duration and number of training sessions are reported. We believe that these two factors could affect the effectiveness of VR-based training. Furthermore, when using the Kirkpatrick model, a significant imbalance can be observed in favor of outcomes from the ‘Reaction’ and ‘Learning’ levels compared to the ‘Behavior’ and ‘Results’ levels. The last of these was not used in any of the 330 reviewed studies. These results highlight the importance of research on the effectiveness of VR training. Taking into account the identified methodological shortcomings will allow for more significant research on this topic in the future
