Live data from Hacker News

Coming to Agreement, a logic puzzle for Oxford admissions interviews

jdh.hamkins.org

11–20 of 99 posts

Re: Coming to Agreement, a logic puzzle for Oxford admissions interviews

#11
> Some student candidates had proposed an interesting idea of trying to blend the two colors. [...] I like this idea a lot, but it seems problematic in light of the fact that we don’t have such a clear and unambiguous means of combining colors.

Not if we use RGB, send the color as a tuple of three numbers and average both tuples (taking the floor for example if one of the numbers is odd).

Re: Coming to Agreement, a logic puzzle for Oxford admissions interviews

#12
There's solving the problem - and there's solving the scenario.

I'd presume that a logical contestant would google blue to be the most frequently chosen random colour, and the two of you would just scream "blue" at each other other and then you'd end the game.

Re: Coming to Agreement, a logic puzzle for Oxford admissions interviews

#13

I'm surprised more people didn't recognize the two generals problem.

It’s not the two generals problem because you can be sure that your companion gets the message (both literally a d figuratively). The two generals problem is about inherent uncertainty, while the given problem has full transparency.

Re: Coming to Agreement, a logic puzzle for Oxford admissions interviews

#14
One of the difficulties is deciding on a strategy that would work even if the other player used the exact same strategy on you.

My solution is to say something like: ‘I will nominate a colour next round. If we both nominate the same colour, I will say that colour and end the game next round. If anything else, I will nominate a different colour, proceeding alphabetically.’

Of course, it would depend on what message you receive that round - there’s probably no one size fits all approach, such as the issues of both people using an unyielding strategy. So maybe you’d have a clause which says, if the other player gives an ultimatum message, then you will go along with that.

I don’t think there’s a perfect solution here, but I could be wrong.

Re: Coming to Agreement, a logic puzzle for Oxford admissions interviews

#15
post #13

I'm surprised more people didn't recognize the two generals problem.

It’s not the two generals problem because you can be sure that your companion gets the message (both literally a d figuratively). The two generals problem is about inherent uncertainty, while the given problem has full transparency.

But isn't that exactly what the "Pigeon variation" the article mentions is?

Re: Coming to Agreement, a logic puzzle for Oxford admissions interviews

#16

These puzzles would make horrible college admissions tests. They hardly qualify as interview questions. This typpe of problem is nearly impossible for folks that have never heard a similar test and nearly trivial for someone who has heard ~3 like it.

This is general problem with modern public founded education system - it prizes memorization of repetitive schemes - as it's easy to check on the mass scale who is able to memorize these schemes. It's several magnitudes harder to check who really is a material for a scientist among same large population of candidates. I was educated in top university in my Central European country and to this day cannot shake off memories of people who passed calculus exams by memorizing solutions of integrals instead of understanding how to solve them. It was a general scheme - mediocre students interested only in "getting paper" aka diploma were passing exams mostly flawless some of them even get scholarships[sic(k)!] while people interested in actually understanding material and doing projects by their own (most students were making projects in groups and changing only minor details and teachers were pretending they do not see that) were struggling within that system. As the system has memorization without understanding and cheating as a fundamental of it's construction and people who resist following that pathological scheme were simply penalized. Attempts to rationalize with academic teachers in many cases resulted in absurd remarks of "everyone have equal requirements for passing classes". Puke inducing every time I think about that.

Re: Coming to Agreement, a logic puzzle for Oxford admissions interviews

#17
post #12

There's solving the problem - and there's solving the scenario. I'd presume that a logical contestant would google blue to be the most frequently chosen random colour, and the two of you would just scream "blue" at each other other and then you'd end the game.

This is not true in a live and death scenario, because with asymmetric payoffs like that - termination being the down side risk - it is not at all „rational“ to jump to the answer that gives the highest probability of success, if that answer still has a non-zero risk of death.

Re: Coming to Agreement, a logic puzzle for Oxford admissions interviews

#18
post #9

„Imagine the stakes are very high—perhaps life and death.“ The only acceptable solution for perfectly rational players in the case of „death“ as possible down side while only having „live“ as a potential upside would be to extend the game indefinitely by telling the co-player that you will never agree on a different strategy than infinite play - all possible rewards, zero downside risk! Where can I get my ticket to O…

Well in that case, you just don't answer. Your buddy on the other side also wouldn't be expecting you to, so they'll just leave the game running indefinitely as well.

Re: Coming to Agreement, a logic puzzle for Oxford admissions interviews

#19
post #17
post #12

There's solving the problem - and there's solving the scenario. I'd presume that a logical contestant would google blue to be the most frequently chosen random colour, and the two of you would just scream "blue" at each other other and then you'd end the game.

This is not true in a live and death scenario, because with asymmetric payoffs like that - termination being the down side risk - it is not at all „rational“ to jump to the answer that gives the highest probability of success, if that answer still has a non-zero risk of death.

Then as I mentioned below, you neither of you send a message and the game remains open indefinitely.

Re: Coming to Agreement, a logic puzzle for Oxford admissions interviews

#20
post #18
post #9

„Imagine the stakes are very high—perhaps life and death.“ The only acceptable solution for perfectly rational players in the case of „death“ as possible down side while only having „live“ as a potential upside would be to extend the game indefinitely by telling the co-player that you will never agree on a different strategy than infinite play - all possible rewards, zero downside risk! Where can I get my ticket to O…

Well in that case, you just don't answer. Your buddy on the other side also wouldn't be expecting you to, so they'll just leave the game running indefinitely as well.

Exactly. Asymmetric payoffs lead to strange behavior.
Post reply on HN