mrparrot · HackerTrans

The worrying part is that the winning entry would bust immediately if someone wrote a single test to check if the computed numbers are correct. I'm not sure what I find more disconcerting: That the judges considered this a feasible attack or that they are probably right.

mrparrot

há 3 anosdiscuss

Last year there was a brief period where the same ticket cost 9€/month. It was a success but discontinued for mainly political reasons. There is a fund however where you subscribe for 9€ and if you get caught riding without a ticket they pay your fine. Unfortunately, the threat of prison makes this idea not sustainable. But it is a nice display of hacker spirit.

mrparrot

há 3 anosdiscuss

I think what you say might be true. I once found a dumbed down version which goes like this: (A simplified version of Mia [0])

On your turn, you secretly roll a die and then make a statement about what number you rolled. The next player may then call your bluff. If you lied, you lose, otherwise they lose. Or they may roll again, but must claim to have rolled something higher than whatever you rolled. If you don't lose, you win.

Suppose you have to explain your (mixed, i.e. involving randomness) strategy to other players before playing. This is a simulation of the realistic situation of playing many times and other players learning your strategy.

Let us examine the situation where you are given a 4 from the previous player and you decided to roll. (You would have to prove that this can be a correct move, but what follows is in principle true in any situation where you roll.)

If you roll a 5 or 6, you say so. But if you roll a lower number, you have to claim a 5 or 6 regardless. If you announce a 6, you lose instantly, because the next player has no chance of rolling higher, so they must call your bluff. Thus in a single game the correct move is to announce a 5.

But since the other players know your strategy, you can increase you chances of them believing you have a 5 if you sometimes claim a 6 and thereby forefeit the game. It is an easy calculation to see that this strategy yields more wins than always claiming a 5 in this situation.

I think this is analogue to the poker example: Play a clearly bad move and thus gain an advantage by being unpredictable. In my example it is not so hard to see that the advantage can in principle outweigh the cost of playing bad moves.

[0] https://en.wikipedia.org/wiki/Mia_(game)

mrparrot

há 3 anosdiscuss

But with this argument you could blackmail someone whether or not you have some evidence.

mrparrot

há 4 anosdiscuss

That is a fair point and I realize that I do remember some facts because the questions on the respective exams were, in my opinion back then, terrible. I would, however, consider most of these facts trivial by now. Still, it has played a role in my understanding of the matter.

On the other hand, these tests are usually meant to evaluate learning progress and are not themselves thought of as teaching material. I find this quite unfortunate and would really wish that an exam were more like an individual learning session but here we are.

Thus, while this question as it it might advance understanding, it might at the same time hinder progress because someone will fail the exam for giving the wrong answer.

Or for spending too much time on a question that someone who failed to get the lesson answered in a second. This is an answer to what if the question is not meant to be answered "correctly" but just to stimulate learning. Unless the whole exam does not get graded - which would be great and hilarious at the same time - I fail to see the fairness here.

mrparrot

há 4 anosdiscuss

Testing information retention is fine. But the information "The textbook claims A is the correct answer" is not worth remembering, is it?

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