I have seen this example before. I actually do not blame the students at all for the following reasons (some taken from other comments)
1) They are thinking out loud, so seeing that some aspects points it could be heat conduction(after all that would be the typical reason for most temperature discrepancies withing an item) then they scream "heat conduction" as an invitation for closer look which is a valid (as pointed by other commentors) method of thinking
2) They are screaming the highest probable answer they can think of. Magic and heat conducti... (read more)
I've not seen anybody mention those students who said "strange metals in the plate" in particular, and I'd like to argue for them. Their answer was not a password (the teacher never mentioned it), and actually shows correct anticipation-controlling beliefs! That is to say, they noticed that the observed outcome is not what they would have predicted, and looked for some hypothesis that explained why the heat gradient is reversed. Working from the incorrect assumption that they are seeing a stationary state, they guessed a hidden means of transporting heat from the heater to the far end of the plate, e.g. an insulated internal layer. I might be overfitting on this few-word detail, but I think this answer is on average very early in search orderings of those with qualitative but correct visualization of heat conduction, and I don't see other equally simple reasons why the students would have said this.
Of course, I also agree with the rationalist point that this answer should still feel a bit forced, trigger a listing of assumptions, which on average hits "stationary state" very early for simple physics problems.
I have seen this example before. I actually do not blame the students at all for the following reasons (some taken from other comments)
1) They are thinking out loud, so seeing that some aspects points it could be heat conduction(after all that would be the typical reason for most temperature discrepancies withing an item) then they scream "heat conduction" as an invitation for closer look which is a valid (as pointed by other commentors) method of thinking
2) They are screaming the highest probable answer they can think of. Magic and heat conducti... (read more)