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This is an old revision of this page, as edited by 24.27.16.22 (talk) at 14:02, 8 December 2010 (Undid revision 401213842 by Gerhardvalentin (talk) please don't remove people's deserved posts). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Template:Mediation

Featured articleMonty Hall problem is a featured article; it (or a previous version of it) has been identified as one of the best articles produced by the Wikipedia community. Even so, if you can update or improve it, please do so.
Main Page trophyThis article appeared on Wikipedia's Main Page as Today's featured article on July 23, 2005.
Article milestones
DateProcessResult
May 3, 2005Peer reviewReviewed
June 25, 2005Featured article candidatePromoted
January 29, 2007Featured article reviewKept
May 18, 2008Featured article reviewKept
Current status: Featured article
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Need for page protection

The article was recently placed under temporary protection due to edit waring. That protection has since expired. Further edit waring will result in the article being protected indefinitely. Hopefully the mediation will produce a climate of collaborative editing. In the mean time, would editors be willing to refrain from editing the article? Thank you. Sunray (talk) 21:17, 6 October 2010 (UTC)[reply]

Would you categorize the deletions I made last week that were reverted and led to the page protection as 'major edits'? Glkanter (talk) 21:40, 6 October 2010 (UTC)[reply]
Or replacing the paraphrased solution with the exact quote? Glkanter (talk) 17:33, 7 October 2010 (UTC)[reply]
I think it best not to edit the article at all, so I've changed the wording to reflect that. Sunray (talk) 21:12, 7 October 2010 (UTC)[reply]

I regret to inform you that I have a 'policy' of not agreeing to self-censorship on Wikipedia. I suggest you have the page protection restored. I'll wait a reasonable amount of time. Glkanter (talk) 21:18, 7 October 2010 (UTC)[reply]

Further simplification of problem to bare skeleton

This problem can be simplified as follows. Instead of arranging doors, cars and goats, host just randomly chooses a number within the set (1, 2, 3). Participant simply needs to guess that number in two chances. Participant tells his guess to host. Host then reveals a number within the set which is neither he himself had chosen nor participant had guessed and adds that number is not the correct answer. At this point he asks participant if he wants to switch this choice. At this point if participant decides to switch then has 66% chance of being correct otherwise 33%.

( I tried to add above section, but got deleted. Can somebody explain, how is this simplification wrong ?) —Preceding unsigned comment added by 120.61.32.199 (talk) 11:43, 14 November 2010 (UTC)[reply]

I reverted it for two reasons. It had very poor grammar with many mistakes, so was difficult to read and unclear. And the probabilities are 2⁄3 and 1⁄3, not 66% and 33% (which don't even add up to 100% so are clearly wrong). Further it is redundant as the information is already in the article.
But see also the note at the top of this talk page: the article; it is under mediation, so editors should not be making significant changes to the article at the moment. That means even if your change was well written and error free it is wrong to add it now.--JohnBlackburnewordsdeeds 12:07, 14 November 2010 (UTC)[reply]
120.61.32.199, your contribution was also not supported by a reliable source. Martin Hogbin (talk) 12:16, 14 November 2010 (UTC)[reply]

rudeness to von Savant

In the explanation of "Why the probability is not 1/2", it mentions that if the host doesn't know which one has a goat, von Savant "correctly replied ...". It's rude to question von Savant's judgement here, especially when he was right. This mathematician revealed a paradox which couldn't be explained by many great minds and now some keyboard warrior is passing approval for him. Why don't we give him a star as well? What a good boy von Savant is.. Owen214 (talk) 11:25, 27 October 2010 (UTC)[reply]

This comment is making no sense at all (vos Savant is neither a mathematician nor male and nobody is really questioning her judgement (at best her explanation from a very particular point of view). Also WP is not in the business of handing out stars (to whoever) ...--Kmhkmh (talk) 15:05, 27 October 2010 (UTC)[reply]
I'm reading this as a suggestion to delete "correctly" as it sounds like we're passing judgment on vos Savant's reply. -- Rick Block (talk) 16:50, 27 October 2010 (UTC)[reply]
If that's the case he was switching subject and object around constantly. leaving us to pure guessing regarding his intended message. Btw. what's going with the mediation?--Kmhkmh (talk) 16:58, 27 October 2010 (UTC)[reply]

Yes, I got mixed up and thought it was a man called von Savant. Either way, it's still rude. If people are sending her mathematical problems to answer, one would think that she could be called a mathematician. Kmh, you seem not to understand how subtelties can make a sentence rude. Mentioning that "vos Savant correctly replied.." implies there was reason to think that her response may not have been correct. It's also rude to talk about me as "he" when I'm actually part of this conversation. Owen214 (talk) 08:14, 5 November 2010 (UTC)[reply]

Considering your inability to write a clear sentence, your contention that subtleties can make a sentence rude is probably not going to be listened to. Especially since the sentence was not rude. It stated the simple fact that vos Savant's reply was correct, a point that is necessary for the discussion to make sense. Finally you were being spoken of, not spoken to so the use of a pronoun is not rude but only an example of saving time and effort. If there had been a fourth poster involved, using he to refer to you could have been ambiguous but it still would not be rude. --Khajidha (talk) 16:14, 24 November 2010 (UTC)[reply]

I AM A MOTHERFUCKING IDIOT. Owen214 (talk) 05:53, 30 November 2010 (UTC)[reply]

Monty Hall code

To help show the logic I submit a Perl program that simulates the Monty Hall problem. Sorry if there is a better way to submit this.

Code
#!/usr/bin/perl

# Monty Hall Problem
# Jason Holm - jason@jasonholm.com
# 29 October 2010

$number_of_plays = 1000; # How many times the game is played.
$verbose = 1;            # Display plays

print "Playing $number_of_plays time(s)\n\n";

for ($plays=0;$plays<$number_of_plays;$plays++) {
 $winning_door = int((rand() * 3) + 1);
 $player_pick = int((rand() * 3) + 1);
 $player_switch = int((rand() * 2) + 1);
if ($verbose == 1)
{
 print "Player picks door number $player_pick\n";
}
 do
 {
 $goat_door = int((rand() * 3) + 1);
 } while ($winning_door == $goat_door || $player_pick == $goat_door);
if ($verbose == 1)
{
 print "Player is shown door number $goat_door as having a goat...\n";
 print "User is asked if they want to pick the other door...";
}
 if ($player_switch == 1)
 {
if ($verbose == 1)
{
 print "player wants to switch doors!!!\n";
}
 do
 {
  $switch_to_door = int((rand() * 3) + 1);
 } while ($player_pick == $switch_to_door || $goat_door == $switch_to_door);
 $player_pick = $switch_to_door;
 }
 else
 {
if ($verbose == 1)
{
 print "player does not want to switch doors...\n";
}
 }
if ($verbose == 1)
{
 print "The winning door is number $winning_door!!!\n";
}
 if ($player_pick == $winning_door)
 {
 if ($player_switch == 1)
 {
if ($verbose == 1)
{
  print "Players wins after switching doors!!!\n";
}
  $SAW++;
 }
 if ($player_switch == 2)
 {
if ($verbose == 1)
{
  print "Players wins after keeping their choice the same...\n";
}
  $KAW++;
 }
 }
 else
 {
  if ($player_switch == 1)
 {
if ($verbose == 1)
{
  print "Players loses after switching doors!!!\n";
}
  $SAL++;
 }
 if ($player_switch == 2)
 {
if ($verbose == 1)
{
  print "Players loses after keeping their choice the same...\n";
}
  $KAL++;
 }
 }
if ($verbose == 1)
{
print "---------------------------------------------------------------------------------\n";
}
}
print "* * * RESULTS * * *\n";
print "\n";
print "Switch and Win: $SAW\n";
print "Kept and Wins: $KAW\n";
print "Switch and lose: $SAL\n";
print "Kept and loses: $KAL\n";

— Preceding unsigned comment added by 131.151.49.156 (talk • contribs) 18:15, 29 October 2010 (UTC)[reply]

There are implementations in a variety of languages at wikibooks:Algorithm_Implementation/Simulation/Monty_Hall_problem. -- Rick Block (talk) 01:43, 30 October 2010 (UTC)[reply]

How about the information angle ?

How about first establishing what actual information is present after the host opens the door instead of playing with probebilities that become irrelevant once the door gets opened? Call it a methodological problem if you like. Probabilities of guesses can be mapped to presence and absence of information. The difference is that information based reasoning points clearly what's relevant and what's irellevant. Relevant is that player had new info which gives him 1/2 chance if he tosses a coin and chooses again at random. His first choice is irellevant since he didn't get any info about that choice, he only got infor that new choice with better ods is possible. If we believe that a random choice under uncertainty gives the best odds, then he will improve his chances only if he makes a new random choice, not a forced one.

Information-wise the 2 cases from initial state are merged when new information is provided - they don't exist anymore in the new state, they are indistinguishable. Same applies to the case with 1 mil doors. If player makes forced choice he remains in the prior state with much lower odds - he's not using new information. If he wants to use new information then he has to toss the coin again in order to realize the new state.

Another way to look at it is to realize that in an assembly only a random choice can select new configuration and all forced, non-random transitions are equivalent and confined to the same configuration.

His actual odds still improve from 1/3 to 1/2. ZeeXy (talk) 13:21, 3 November 2010 (UTC)[reply]

(Attempt to) Pick wrong and increase the chances of switching right, or (Attempt to) pick right and not know until it's too late. Metaphysically speaking, I'd rather wing it. 70.15.11.44 (talk) 05:28, 4 November 2010 (UTC)[reply]
When wondering where the car is, you shouldn't just use the hard information which you have in front of you, but also the likelihood that that information came to you under the different scenarios which concern you. You chose Door 1. The host is twice as likely to open Door 3 if the car is behind Door 2 than if the car is behind Door. 1. When the game is repeated many times, the car will be behind Door 2 twice as often as it is behind Door 1, within those occasions that you chose Door 1 and the host opened Door 3.
Forget about probability, forget about information. This is about very simple arithmetic. Richard Gill (talk) 07:20, 5 November 2010 (UTC)[reply]

Wrong. If a host opens #3 you don't know if that's because you missed or guessed #1 and no imagination can help you. If you automatically switch to #2 that's equivalent to picking #2 in the first place -- he'd still open #3. Now what? :-) He could even let you keep switching till you turn blue. That's why he can be "generous" - coz you are at 50% ignorance and there's nothing that can help you. You could have started with 100 doors and he could have let you switch every time he closed a door and you'd still be in exactly the same state. That's why I said that information-wise prior states are merged as a result of the new info - they are indistinguishable, there is no observable difference. Your first 98 choices are irellevant for the new state -- you are still in a state of 50% ignorance. The only thing you can do to improve your chances in any 50% ignorance state is to toss a fair coin.

Wrong, wrong. We are told as part of the problem statement that the quizmaster knows where the car is hidden, that he will always open a door revealing a goat, and that he will always offer us the opportunity to switch to the other still closed door. Richard Gill (talk) 13:22, 6 November 2010 (UTC)[reply]

Here's example with a real statistical ansamble

Say you were choosing among 3 presidential candidates and one got killed. Does that automatically make the one you haven't picked a 2/3 winner? :-) Then it has to apply to all other people who picked one of these 2. All these people are now real statistical ansamble - genuine massive sample of random choices with equal probabilities and you can clearly see that your particular initial choice is irellevant. Assume totally split election, every candidate having 1/3 before one got killed and assume no one really cares - everyone just wants to vote for the winner since then they get a coin if they voted for a winner. Suppose they all follow your automatic switch tactics and the 3rd voter set gets split equally. No one wins. What's the best chance of voting for the winner you have? 50% What the sole way to insure that someone does win and thereby 50% of you achieve the goal -- that no one does anything authometically but everyone tosses a coin. Why? Because fair coin toss is never 100% fair with finite number of tosses. Only the act of everyone tossing insures the winner. This is probably the best illustration how irellevant and blocking automatic switching is and how you do need to toss in order to actually realize the chance presented by new information.

This is all very different from a situation in which there would be some underlying cause and your sampling is really just measuring it since then you would expect sampling to converge with a very high probability. Without underlying cause it takes infinite number of samples to realize your statistics and that's strictly historical and completely irellevant for a particular singular trial. That's the part people easily forget when they start deluding thelselves with abstract statistics -- it's irellevant for a particualr sample unless there's underlying cause which will ensure rapid convergence. That's the sole thing that makes sampling worth anything -- if there is underlying cause there will be fast convergence. Have to remind you that theoretical limit for a big number rule to apply is infinite number of samples.

Go tossing coins and see how long runs of equal values you are going to get and how huge deviations from imagined 1/2 you are going to get. ZeeXy (talk) 12:44, 6 November 2010 (UTC)[reply]

Maybe it would be best if the participants in this discussion only made reference to reliably published sources, as a method of discussing changes to the articles. I'm sure there are various more appropriate forums elsewhere on the internet that welcome spirited debate on the mathematics and logics of the MHP. Glkanter (talk) 12:52, 6 November 2010 (UTC)[reply]


This another typical response to the MHP article. Everyone wants to know why/how/if the answer is 2/3 rather than 1/2. Martin Hogbin (talk) 10:36, 6 November 2010 (UTC)[reply]

@ZeeXy - if you'd like to discuss the mathematics behind the problem, I'd suggest we move this thread to the /Arguments subpage. If you're suggesting a change to the article, please say what change and on what source (or sources) you'd base that change. -- Rick Block (talk) 15:16, 6 November 2010 (UTC)[reply]
Rick, there shouldn't *be* an 'arguments' page. Arguing the math/logic of the MHP is no more appropriate for a Wikipedia article talk page than discussing the greatness of your favorite musical performer with like-minded fans. The 'arguments' page should be deleted, rather than encouraged. Talk pages are for discussing editing Wikipedia articles. Glkanter (talk) 15:31, 6 November 2010 (UTC)[reply]
The point of the /Arguments page is to have a place for these sorts of discussions, which are not directly related to editing the article, to be held. It is more or less like the Wikipedia:Reference desk - but with a specific focus on the MHP. There's one for various other articles on controversial topics, like 0.999.... You are absolutely correct that THIS page is for discussing editing the article. If you strongly feel the need to see a community consensus about whether the Arguments page should be deleted, please open a discussion at Wikipedia:Miscellany for deletion. -- Rick Block (talk) 17:23, 6 November 2010 (UTC)[reply]

Thanks for the suggestion. I may do that. If its a Reference desk item, well, then it belongs at the Reference desk. Or, I could just take the page off my Watchlist... Glkanter (talk) 21:55, 6 November 2010 (UTC)[reply]

Recent overhaul and state od the mediation

First of all thanks to all who put effort in the recent overhaul, which from my perspective works well overall.

I minor nitpicking I'd have though is the (incomplete) quotation of Behrends in the sources of confusion section. It should be mentioned while Behrends considers both answers as correct he does consider them as 2 slightly different problems or questions at least.

Another I'd like to know is whether the conflicting parties in the mediation are happy with the current version (or at least can live with it) or whether we still have (major) disagreements and an potenial editing conflict down the line. --Kmhkmh (talk) 15:46, 14 November 2010 (UTC)[reply]

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