Mark Collins made an interesting comment at yesterday's research meeting. Something along the lines of 'would I be testing their spatial knowledge at a subsequent time point in order to identify any differences in knowledge retention?'
It's a good point and not something I had really considered before. For one thing I hadn't constructed any research questions related to this point. The ethical issues associated with the design of my study also kind of preclude longitudinal testing to assess knowledge retention as participants need to be offered experience in the alternative arm (intention or control) after the post-test in case there is any difference in knowledge enhancement. If this wasn't offered then one group may be advantaged and attain better module scores as a result. Possibly. So, it would therefore be impossible to assess differences in knowledge retention between the study arms as participants will have had exposure to both intervention and control.
It may still be an interesting phenomenon to explore in a subsequent project although a number of other studies have found NO significant differences in knowledge retention between VR and conventional teaching methods. e.g. see here (with regards engineering) or here (Hall 1998). There may be a difference in knowledge retention, however, where the relevant knowledge depends on spatial 3D cognition (e.g. navigation) so could be something to consider further in the future. For the time being though I don't think it has a place in this work.