I have a related, but different, question about what the classifier is discriminating on. The article quotes Kraemer as saying “in the study, we found that when engineering students looked at images of real-world structures, the students would automatically apply their engineering knowledge, and would see the differences between structures such as whether it was a cantilever, truss or vertical load.” This makes me wonder whether the algorithm is discriminating on knowledge of engineering terminology, rather than what the subjects understand of the physics involved. I am curious as to how the non-engineer subjects who got the answer right compare to the engineers.

Update: on reading the paper, it seems that the goal of the experiment was to distinguish between engineers and novices, and it conflates 'knowledge' with 'understanding', so the claims that the discrimination is on the basis the subjects' understanding of the issues appears to be editorial overreach.