In the present context, the scarce resource can be identified as the cognitive investment required by the learner. It is not a goal to remove the required investment. Rather, it is desirable to allocate those resources wisely. Ellard et al. [7], noted the problem with cross curriculum simulators, and describe the same sentiment: to maximise the number of concepts that can be transferred, while minimising spurious complexity and unnecessary detail that must be imparted.