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Re: [Phys-l] Monty Hall problem



They say an insult hurts in direct proportion to its accuracy.

Recently Chuck Britton wrote:

this pedantic diatribe

get real!

opps, this is a physics list.

Insulting the entire list is probably not a good strategy
for winning the argument.

That door WILL have a goat behind it because we are engaged
in a Game Show instead of purely pedantic exercise.

It may be "obvious" to some folks that the door "WILL" have a
goat behind it. It is not however true in the real world, as
John M. has pointed out.

This is the second time today that a certain idée fixe has been
defended by the use of made-up facts (as opposed to actual factual
facts).

get real!

Tu quoque!

In the world I live in, many games are adversarial. Assuming
that the other participant in the game -- Monty in this case --
is neutral (or an ally) is quite an assumption. If you really
think this is a real-world assumption, I look forward to playing
poker with you.

get real!

Physician, heal thyself!

The first thing any real-world analyst would do would be to
ask "what is the ensemble here?"

Marilyn Our Scholar has given us only a single element, presumably
drawn from some ensemble ... and from that we are supposed to
infer enough about the ensemble in order to draw conclusions
about the probabilities. If you think that is even remotely
representative of the real world, you really need to get out
more.

Maybe in textbook end-of-chapter exercises the probabilities
are always IID and the other player is always your ally ... but
not in any real world I know of.

http://en.wikipedia.org/wiki/IID

Marilyn did -- belatedly -- set forth her assumptions and
admit that they were in fact assumptions. She was however
quite wrong to defend her position by saying "anything else
is a different question" when in fact her original version
of the question was -- and is -- open to multiple interpretations.
Forsooth her "rules" do not even conform to the actual rules
used by the actual Monty Hall on the actual show.

The best strategy is to always switch.

That may be obvious to you ... but it's not actually true.
It is not the correct answer to the original question.

The proof that it is not "always" the best strategy has
already been given multiple times in this thread: If Monty
is your adversary, and has the option to not offer a switch,
then accepting the switch (when offered) is the *worst*
possible strategy. Again: If you don't believe this could
happen in the real world, I look forward to playing poker
with you.

There are established procedures for dealing with ill-posed
questions. Generally the first step involves recognizing
that the problem is in fact ill-posed.
http://www.av8n.com/physics/ill-posed.htm