People are stupid

[MrL_JaKiri]

Originally Posted by sniborp

how is it counter intuitive? less doors = more chance?

Because, in most peoples experience, changing your mind doesn't double your chance of success?

Most people answer "No" to the question of "Would you change door?" simply because they assume that because there are two doors the chances of the prize being behind either one is 1/2.

[Tomkat]

Originally Posted by sniborp

Seriously how the **** is that hard to understand? 3 doors, 1/3 chance, got it wrong, then my chance of getting it right increases if i change because theres only 2 doors now? OMFGWTFHTFWOAHNEVERHOWCANTHATBE?!?!?!?!

I swear i would have found that easy in primary school....

That isn't the concept at all. The question is "Do you change doors". Not "is there more chance of getting it right before or after one door has been removed".

[Cannon_Fodder]

Clarify for me, theres a prize behind one door you want to win. you dont get it first time so people apparently will stick and that helps them win the prize??

thats like sticking on two aces in 21.

[Phalon]

I'll get the wood for the crucifix.

[TheBerk]

ermm... i might have missed this already, but does monty open the door you choose if you get it right? and only opens a 'wrong' door if your incorrect? meaning you need to change doors to win. or did i miss something major whilst reading this thread (and links)

[Tomkat]

Originally Posted by sniborp

Clarify for me, theres a prize behind one door you want to win. you dont get it first time so people apparently will stick and that helps them win the prize??

thats like sticking on two aces in 21.

Sigh.

No.

There are three doors.
One contains the prize.
You're asked to choose one (you don't get to see what's inside it).
Then one of the other two (that you didn't choose) is eliminated, as you're told it has nothing in it.
The question is: Is it a good idea to change your choice to the other door, or not?

[TheBerk]

so it makes no difference if you change or not then as each of the 2 remaining doors has an equal chance of having the prize behind it?

[SYMM]

someone please die.

[Nodrog]

Originally Posted by TheBerk

so it makes no difference if you change or not then as each of the 2 remaining doors has an equal chance of having the prize behind it?

No, you should change because the other door has a 2/3 chance of having the prize behind it.

[Sarina_Joy]

I wish to thank the stupid people in this thread for giving me a headache. The headache came on after I was forced to bash my head against my monitor. Bastards.

[MrL_JaKiri]

Originally Posted by sniborp

Clarify for me, theres a prize behind one door you want to win. you dont get it first time so people apparently will stick and that helps them win the prize??

thats like sticking on two aces in 21.

Oh for the love of god.

This will be bolded so hopefully people will read it and think about why I've posted it.

There are three doors. One of them has a prize behind. The other two do not.

You choose a door. IT IS NOT OPENED.

One of the other two doors is then opened, and it is revealed to you that it had no prize behind. So either the door you have has the prize, or the other door has the prize.

You are offered the chance to change the door you have chosen.

DO YOU DO IT?

Or, to put it another way

You are presented with 3 doors (A, B, C) only one of which has something valuable to you behind it (the others are bogus).
You do not know what is behind any of the doors
You choose a door
Monty then counters by showing you what is behind one of the other doors (which is a bogus prize), and asks you if you would like to stick with the door you have, or switch to the other unknown door
The question is should you switch?

To quote it (aside from one small change due to editing out the first bit) verbatim from the site quoted last page and on the top of this page.

Read.

Comprehend.

Post.

In that order, and no other.

[roadrunner_0]

im sure that some of the people on this page cannot be serious, they must be winding us up

[MrL_JaKiri]

Originally Posted by roadrunner_0

im sure that some of the people on this page cannot be serious, they must be winding us up

Oh I don't know, I've not really seen any evidence to the contrary of the "they're really dump" hypothesis.

[pig]

i understand this, the question is do I switch if im in this predicament, or do i stick??!!?!?!

[LHC]

You switch

[TheBerk]

im understanding the situation, im just failing to see what difference it makes if you stick or switch, or maybe i am dumb and thats the point, but meh

[Summanus]

There is a 2/3 chance that the prize is in an option you didn't choose. By removing a box, this stays the same, though it has a greater chance of being in the box you didn't choose, as now there is only one other option

[roadrunner_0]

seriously, read the link that T&F posted, it explains this

[TheBerk]

surely by removing a box you are reducing the possibilities to 1 in 2 instead of 1 in 3 as now you only have 2 to choose from. the 3rd box is effectively out of the question, or is this the reason i refused to take stats at a-level coz they can make anything appear as anything else.

[MrL_JaKiri]

Originally Posted by TheBerk

im understanding the situation, im just failing to see what difference it makes if you stick or switch, or maybe i am dumb and thats the point, but meh

Look at the site linked. You know, the one with the answer.

[MrL_JaKiri]

Originally Posted by TheBerk

surely by removing a box you are reducing the possibilities to 1 in 2 instead of 1 in 3 as now you only have 2 to choose from. the 3rd box is effectively out of the question, or is this the reason i refused to take stats at a-level coz they can make anything appear as anything else.

You can represent things many ways using statistics, but you appear to have taken this to mean that all statistics are meaningless, which blatantly isn't true (all of science, for example, is based on statistical methods. Do you like that computer you're using?)

If you're worried about the varying validity or interpretation of statistics, and the way they're presented, then you did exactly the wrong thing by not taking A-level statistics because the one demographic that people can't fool with statistics is that of people who understand statistics.

Furthermore, this is not some statistical trick. It is ABSOLUTELY TRUE.

[TheBerk]

ive looked at the answer, and ive finally understood where people are coming from. but to me it looks like stats, ie lies, it makes sense on paper, but tbh, whats the difference, once theres 2 doors left your left with only 2 options 1 of which is correct

[Summanus]

Originally Posted by TheBerk

surely by removing a box you are reducing the possibilities to 1 in 2 instead of 1 in 3 as now you only have 2 to choose from. the 3rd box is effectively out of the question, or is this the reason i refused to take stats at a-level coz they can make anything appear as anything else.

It's conditional. If I flip a coin twice, and it lands heads the first time, the probability of it landing heads the second time is 1/4, rather than 1/2.

if it was isolated, it would be 1/2

[TheBerk]

right, ive got where all this is coming from, now forgive me while i stick with my original door because i dont feel it matters a damn

[MrL_JaKiri]

Originally Posted by Summanus

It's conditional. If I flip a coin twice, and it lands heads the first time, the probability of it landing heads the second time is 1/4, rather than 1/2.

No it isn't.

[roadrunner_0]

Originally Posted by Summanus

It's conditional. If I flip a coin twice, and it lands heads the first time, the probability of it landing heads the second time is 1/4, rather than 1/2.

if it was isolated, it would be 1/2

this is the point where everyone knows you are either trolling or incredibly stupid

[MrL_JaKiri]

Originally Posted by TheBerk

right, ive got where all this is coming from, now forgive me while i stick with my original door because i dont feel it matters a damn

OK, little demonstration of all the possibilities.

You have 3 doors, A, B and C.

Lets say the prize is behind door A. This is entirely arbitrary, and because the doors are exactly similar, the probabilities will be identical and you can change the "order" of the doors just by renaming them.

You have a 1/3 chance of picking door A.

If you pick door A and change, you lose.

If you pick door A and stick, you win.

You have a 1/3 chance of picking door B.

If you pick door B and change, you win.

If you pick door B and stick, you lose.

You have a 1/3 chance of picking door C.

If you pick door C and change, you win.

If you pick door C and stick, you lose.

These represent the sum total of possibilities.

If you change, you win 2/3. If you stick, you win 1/3.


It's undeniably true. This is not a "I'm pretty sure it's true" kind of area. This is a solid fact, and, given the axioms of mathematics, is utterly and totally true, in an "impossible to disprove ever" kind of way.

You have a 1/3

[Nodrog]

Originally Posted by TheBerk

surely by removing a box you are reducing the possibilities to 1 in 2 instead of 1 in 3 as now you only have 2 to choose from. the 3rd box is effectively out of the question, or is this the reason i refused to take stats at a-level coz they can make anything appear as anything else.

Imagine that I've thought of a number between 1 and a million and written it down on a bit of paper, and I'm asking you to try and guess what it is. After your guess, I will eliminate 999,998 answers which are wrong. Would you like to switch?

[MrL_JaKiri]

Originally Posted by TheBerk

ive looked at the answer, and ive finally understood where people are coming from. but to me it looks like stats, ie lies, it makes sense on paper, but tbh, whats the difference, once theres 2 doors left your left with only 2 options 1 of which is correct

This is one of those occasions where I replied to a post before it was made. Look at the post about this (your) one.

[TheBerk]

ive already said i understand where this is all coming from, i know its written and proved etc. but in my own little mind ill continue to read the chances from the second step (one door revealed)

[MrL_JaKiri]

Originally Posted by TheBerk

ive already said i understand where this is all coming from, i know its written and proved etc. but in my own little mind ill continue to read the chances from the second step (one door revealed)

[TheBerk]

Originally Posted by Nodrog

Imagine that I've thought of a number between 1 and a million and written it down on a bit of paper, and I'm asking you to try and guess what it is. After your guess, I will eliminate 999,998 answers which are wrong. Would you like to switch?

personally i wouldnt switch, but thats just my mind set, im a stubborn git

[MrL_JaKiri]

Originally Posted by TheBerk

personally i wouldnt switch, but thats just my mind set, im a stubborn git

When an invading alien species puts this little brainteaser in front of you, you'd wish you weren't so stubborn, and, in the end, truth will win out.

[Summanus]

Originally Posted by MrL_JaKiri

When an invading alien species puts this little brainteaser in front of you, you'd wish you weren't so stubborn, and, in the end, truth will win out.

Not only do aliens not exist, it is improbable that they do

[LHC]

He'd be glad he was stubborn if he stuck and got it right!

Although that's 50% less likely to be the case.

[pig]

Originally Posted by MrL_JaKiri

OK, little demonstration of all the possibilities.

You have 3 doors, A, B and C.

Lets say the prize is behind door A. This is entirely arbitrary, and because the doors are exactly similar, the probabilities will be identical and you can change the "order" of the doors just by renaming them.

You have a 1/3 chance of picking door A.

If you pick door A and change, you lose.

If you pick door A and stick, you win.

You have a 1/3 chance of picking door B.

If you pick door B and change, you win.

If you pick door B and stick, you lose.

You have a 1/3 chance of picking door C.

If you pick door C and change, you win.

If you pick door C and stick, you lose.

These represent the sum total of possibilities.

If you change, you win 2/3. If you stick, you win 1/3.


It's undeniably true. This is not a "I'm pretty sure it's true" kind of area. This is a solid fact, and, given the axioms of mathematics, is utterly and totally true, in an "impossible to disprove ever" kind of way.

You have a 1/3

I get it now. thanks

[MrL_JaKiri]

Originally Posted by LHC

He'd be glad he was stubborn if he stuck and got it right!

No, because the aliens are looking for people who understand statistics rather than people with dumb luck so they get the most intelligent of us and make us breed with their women. They'll also be using advanced telepathy to make sure you're using the right reasoning.

[MrL_JaKiri]

Originally Posted by Summanus

Not only do aliens not exist, it is improbable that they do

You can shut up

[TheBerk]

Originally Posted by MrL_JaKiri

When an invading alien species puts this little brainteaser in front of you, you'd wish you weren't so stubborn, and, in the end, truth will win out.

if they set the question and asked which door would have a greater chance of being right i will remember this thread and say 'oh mighty aliens, if i change door my chance of being right will rise to 2/3 instead of 1/3'. and when they ask me if i would like to change i shall say 'verily, i shall stick with my original choice' and be not too surprised when the door they open leads to the voids of space and i die horribly instead of being led to a room filled with nubile six breasted alien females

[Summanus]

Originally Posted by MrL_JaKiri

You can shut up

It is however improbable that they would invade Earth, by the same logic that it is probable they do exist.

Which reminds me - 2 + 2 = 5

[Phang]

Originally Posted by Summanus

It is however improbable that they would invade Earth, by the same logic that it is probable they do exist.

Which reminds me - 2 + 2 = 5

DONT DRAG RADIOHEAD INTO THIS

[Summanus]

Originally Posted by Phang

DONT DRAG RADIOHEAD INTO THIS

I don't listen to Radiohead, which may/may not be a good thing.

[MrL_JaKiri]

Originally Posted by TheBerk

if they set the question and asked which door would have a greater chance of being right i will remember this thread and say 'oh mighty aliens, if i change door my chance of being right will rise to 2/3 instead of 1/3'. and when they ask me if i would like to change i shall say 'verily, i shall stick with my original choice' and be not too surprised when the door they open leads to the voids of space and i die horribly instead of being led to a room filled with nubile six breasted alien females

No because they want people who act logically all the time and therefore they don't want to give the game away so it'll be a sort of double bluff and the people performing the tests won't know what they're looking for only the telepathic overseers so it'll be a classic double blind experiment except that the people telling the people taking the experiment will be those who failed and they're only killed at the end and the people who pass are taken off elsewhere and don't have contact again and so the people running the experiment think that they got it right and the others are dead and this means that they may be able to influence people who are unsure so they don't pass because the aliens only want people who are sure in their convictions and all the others will be killed by a man with a cheese grator.

[MrL_JaKiri]

Originally Posted by Phang

DONT DRAG RADIOHEAD INTO THIS

Yeah, they may be tarred by association.

[edit]

Don't forget to read my post at the bottom of page 2!

[Summanus]

Originally Posted by MrL_JaKiri

No because they want people who act logically all the time and therefore they don't want to give the game away so it'll be a sort of double bluff and the people performing the tests won't know what they're looking for only the telepathic overseers so it'll be a classic double blind experiment except that the people telling the people taking the experiment will be those who failed and they're only killed at the end and the people who pass are taken off elsewhere and don't have contact again and so the people running the experiment think that they got it right and the others are dead and this means that they may be able to influence people who are unsure so they don't pass because the aliens only want people who are sure in their convictions and all the others will be killed by a man with a cheese grator.

'grater'

[Phang]

Originally Posted by Summanus

'grater'

it's spelled 'great'

[MrL_JaKiri]

Originally Posted by Summanus

'grater'

No I wasn't talking about the common household implement I was talking about something the aliens made which was a hybrid between that device and an alligator so the person using it doesn't have their arm go all tired because it will move itself.

[TheBerk]

Originally Posted by MrL_JaKiri

No because they want people who act logically all the time and therefore they don't want to give the game away so it'll be a sort of double bluff and the people performing the tests won't know what they're looking for only the telepathic overseers so it'll be a classic double blind experiment except that the people telling the people taking the experiment will be those who failed and they're only killed at the end and the people who pass are taken off elsewhere and don't have contact again and so the people running the experiment think that they got it right and the others are dead and this means that they may be able to influence people who are unsure so they don't pass because the aliens only want people who are sure in their convictions and all the others will be killed by a man with a cheese grator.

so would i have passed or failed then?

[MrL_JaKiri]

Originally Posted by TheBerk

so would i have passed or failed then?

If you were stubborn, you would have failed and thus would have to run the tests until you finally got taken to pieces by a chappy with a utensil/reptile crossbreed.

[TheBerk]

but i was sure in my convictions