Journal Planesdragon's Journal: A perfect example of science's shortcomings. 23
If you don't know about it already, go read up on the Monty Haul problem. Bear in mind that computer simulation proves Marilyn Vos Savant right.
Now, then, why exactly is she wrong?
A natural inclidng is to jump up and say "she's got to be wrong; there's no way that can be right." A scientific inkling is to say "Planesdragon, you've gone off on a silly Christian rant again. Why must you prove how stupid you are?"
The answer, of course, comes in a closer examination of the problem.
If you choose to always switch, you will win 2/3 of the time.
If you choose to not switch, you will win 1/3 of the time.
But, the desicion to switch does not come until Monty asks his final "will you switch" question. Either you've got the car or you've got the goat--a new possibility that has exactly two outcomes.
I'm just a lowly college drop-out, but I believe that this is an example of "the law of independent trials."
You've lost me. (Score:2)
Are you saying that Marilyn is wrong and the odds of winning are not 2/3 if you switch every time?
Re:You've lost me. (Score:2)
No. What I was saying was that the necessary question isn't "what should I pick", but rather "what are my odds of wining?"
If you go up onto a game show, your odds of making your final desciion are 50/50 -- one is a car, one isn't. I incorrectly failed to account for Marilyn's presumption that the host is playing fair -- somewhat augmented by lack of an actual choice among the various "emphirical tests" Wikipe
Re:You've lost me. (Score:2)
If Monty doesn't know what door the car is and randomly opens one of the remaining doors, then you end up with a 1/3 chance of winning, regardless of whether you switch or not. This is because if Monty opens the car door, you've lost. Switching or staying with your door doesn't make a difference.
If the sponsors can change where the stuff is after the first door is picked, then the
Re:You've lost me. (Score:2)
Sometimes, this is fine. Other times--particularlly over efforts that have any opposition at all--it's a bad thing.
Best example I can think of? The Big Bang theory (and most other astrology) presumes that the fundamental forces of the universe are constant and homogenous. While this is emminently reasonable, it's the sort of thing that needs to be pointed out when people take science's "this is what it looks like" and turn it into "we
Re:You've lost me. (Score:2)
Probably just a typo though, so I will leave it at that.
Re:You've lost me. (Score:2)
2: Christianity has quite a history with astrology, actually. The best example would be the three wise men, but there are likely others in teh various christian bodies of lore.
Remember, the commandment was not "forsake all but your God", it was "have no other Gods before me." If the Big man isn't answering you, there's nothing inherently sinful about turning to astrology. (There may be something inherentily foolis
The reason MVS is right (Score:3, Informative)
Re:The reason MVS is right (Score:2)
The trials are not independent, and that's the non-intuitive part.
Re:The reason MVS is right (Score:2)
d'oh!
The trials are not independent (Score:1, Informative)
I'm probably simplifying this too much (Score:2)
After you have two options to choose from, you can only select either one or the other. One of the 100% chance of failure options is eliminated, leaving two options (a winner and a loser), thus a 50% chance of winning.
At the option to switch, why does the first door have any relevance whatsoever?
Re:I'm probably simplifying this too much (Score:2)
Kids get pounded into their heads in stats classes to watch out for independent events, but these events are NOT independent, therefore that does
Re:I'm probably simplifying this too much (Score:2)
Re:I'm probably simplifying this too much (Score:2)
Re:I'm probably simplifying this too much (Score:2)
Because the host knows which door is the prize door.
The picture is easier with a larger number of doors. Let's say, four. You have a one-in-four chance in picking the right door on your first time--and that's the ONLY time that the door the host doesn't open won't be the prize.
it's nice to know I wasn't the only one who got this one wrong. Although it becomes yet another complaint against scientists that this principle wasn't
Christianity? Science? (Score:2)
Re:Christianity? Science? (Score:1)
Are you sure about that?
The good Christian should beware of mathematicians and all those who make empty prophecies. The danger already exists that mathematicians have made a covenant with the devil to darken the spirit and confine man in the bonds of Hell.
---Saint Augustine
Re:Christianity? Science? (Score:2)
Re:Christianity? Science? (Score:2)
Absolutely nothing more than framing the flow of the article. I could have easily said "married men" or "white guys".
Wikipedia makes me nuts (Score:2)
So the basic explanation is really actually quite simple. There are three possible outcomes:
So there are three posibilities, two of which lead to you winning the car, hence a 2/3's p
argh (Score:2)
IE, you have choice 1, 2, 3.
The correct choice is 2, 1 and 3 being false.
If you pick 1, 3 is revealed, and vice versa.
You never have a 33% chance of winning, nor a 66% chance. You have a 33%
Re:argh (Score:2)
There are four variables involled--winning door, first choice, door shown, and second choice. If you map out all of the possibilities, you wind up with even choices of each--but that doesn't account for the host knowing which is the right door.
It is precisely because the host knows which door is the prize--and so will not pick that one if you haven't--that tilts the odds in the favor of the switcher. Replace the