Not the usual examination howlers but I'm speaking about examiner's howlers. I use to learn more from my own errors than from other people's errors.
Two days ago, after long hours of examination there was this woman who just was brilliant (my usual feedback in these cases: "You could have been a good deal worse and it still would have been A"). I could ask her to apply her book knowledge to very unusual situations or questions and she could do that.

So on the whim of the moment I asked her to apply what she knew about risk analysis (in nuclear power plants) to asteroids coming near to the earth (by the way, I am grateful to McGrath for the idea to this question who a couple of weeks ago, in this thread, said about the assessment of impact probabilities somewhat rashly "One in six million" that's the kind of figure they make up.). It was obvious she never had thought about this before but she did a great job in applying what she knew to an unknown problem.

I then decided with her it would be no risk to ask another difficult question on a field she never had though about before and said: "Let's now move to another field on which you also have not the slightest clue". Her face showed that my wording had also a very different meaning from what I had meant to say. I laughed out loud and did the necessary explaining.


Another one which I rued later a lot for it turned out to be a failed examination in the end (and you may joke with good students but otherwise never): There was a woman who had learned an amazing amount of completely unnecessary and uninteresting details (but didn't see what was truly relevant). I had asked about a learning experiment involving an ape (general idea, outcome only on an qualitative basis).

She knew the author, the journal, the year of publication, the island on which the experiment had been run, the type of food used for rewarding and all that stuff and I listened in growing puzzlement about someone who couldn't tell important from unimportant. I couldn't hold back any longer and blurted out: "If you know all those detail you surely also know the name of the ape, don't you." She beamed at me and said proudly: "Sultan". As I said, I rued that question in hindsight.

Wolfgang