JeffJo
No.As I understand it, your proposal is essentially the principle of indifference applied to a sample space that isn't the same as the stated assumptions of the SB problem, namely your sample space is based on the triple
{Coin,Day,Wakefulness}
upon which you assign the distribution Pr(Heads,Monday,Awake) = Pr(Tails,Monday,Awake) = Pr(Heads,Tuesday,Asleep) = Pr(Tails,Tuesday,Awake) = 1/4. — sime
This probability space includes a distribution says that a single sampling is happening on two days at the same time. Halfers convince themselves that there is no contradiction; after TAILS the "other" awakening is identical, and after HEADS it is not observed. But that doesn't work if we change to DISNEYWORLD.By contrast, the probability space for the classical SB problem is that of a single coinflip C = {H,T}, namely (C,{0,H,T,{H,T}},P) where P (C = H) = 0.5 .
What is non-permitted? It is a functionally equivalent one. Consequence #1 occurs with three of the four combinations, and Consequence #2 occurs with the fourth. The question is only asked with Consequence #2. I'm sorry, but this is a rationalization.But what makes your argument incorrect [is] the use of a non-permitted sample space.
sime
The reason I keep asking for specific answers to specific questions, is that I find that nobody addresses "my sample space." Even though I keep repeating it. They change it, as you did here, to include the parts I am very intentionally trying to eliminate. — JeffJo
There are two, not three, random elements. They are COIN and DAY. WAKE and SLEEP are not random elements, they are the consequences of certain combinations, the consequences that SB can observe. — JeffJo
There are two sampling opportunities during the experiment, not two paths. The random experiment, as it is seen by SB's "inside" the experiment, is just one sample. It is not one day on a fixed path as seen by someone not going through the experiment, but one day only. Due to amnesia, each sample is not related, in any way SB can use, to any other. — JeffJo
Each of the four combinations of COIN+DAY is equally likely (this is the only application of the PoI), in the prior (this means "before observation") probability distribution. Since there are four combinations, each has a prior ("before observation") probability of 1/4.
In the popular problem, SB's observation, when she is awake, is that this sample could be H+Mon, T+Mon, or T+Tue; but not H+Tue. She knows this because she is awake. One specific question I ask, is what happens if we replace SLEEP with DISNEYWORLD. Because the point that I feel derails halfers is the sleep. — JeffJo
JeffJo
You are inserting details into the description of the outcomes, that provide no additional information. It has nothing to do with the [crux? thrust?] of my position. You are obfuscating the sample space in order to suggest an omission.I am simply interpreting the thrux of your position in terms of an extended sample space. — sime
That's just rationalization. I have proposed a model, that I claim represents the SB problem. Whether or not it is "smuggling in new premises" (it isn't, it is extending a premise that already exists), the issues here are only (A) Is the SB problem an example of my model, (B) does my solution apply to the model in general, and (C) how does an unobservable activity affect the solution.This step is methodological and not about smuggling in new premises, except those that you need to state your intuitive arguments, which do constitute additional but reasonable premises.
Look at this way: It is certainly is the case that according to the Bayesian interpretation of probabilities, one can speak of a joint probability distribution over (Coin State, Day State, Sleep State), regardless of one's position on the topic.
And you confuse "measuring the possibility" with "the possibility exists as an outcome." But I devised specific questions to address this exact issue, which have gone completely ignored.But the Sleeping Beauty Problem per-se does not assume that the Sleeping Beauty exists on tuesday if the coin lands heads, because it does not include an outcome that measures that possibility.
Except, you didn't add one. You applied a name that always applies to combination of the other variables. And pardon me for suggesting this, but it seems you are using it to not address my very specific questions, that your "new variable" adds nothing to. If you think it does, then use it as part of your answer to those questions.[You] do require the introduction of a third variable to the sample space in order to express your counterfactual intuition that I called "sleep state" (which you could equally call "the time independent state of SB").
sime
JeffJo
So, are you saying that the week skips from Monday to Wednesday if the coin lands on Heads? What it they wait to flip the coin until Tuesday Morning?All I can say is that we aren't agreeing as to the semantics of the problem. Your sample space includes the counterfactual possibility (H, Tuesday), which isn't in the sample space of the experiment as explicitly defined. — sime
Please, what is inconsistent about it, when we ignore whether she is awake? Do you think she does not know it can happen?You appeal to "if we awoke SB on tuesday on the event of heads" might be a perfectly rational hypothetical...
Why does the problem description have to explicitly say that something which obviously can happen, can actually happen? The description only says that SB will sleep through it, not that it is excluded from the realm of possibility.But that hypothetical event isn't explicit in the problem description.
But who still knows it can happen. All I'm saying is that your "philosophical thought experiment" does not "philosophically eliminate Tuesday from the week" if the coin lands Heads.Furthermore, the problem is worded as a philosophical thought experiment from the point of view of SB as a subject who cannot observe that tuesday occurred on a heads result,
JeffJo
Michael
In summary, rational credence doesn’t float free of betting; it aligns with whatever gets checked. If we check one answer per run, rational calibration yields 1/2. If we check one answer per awakening, rational calibration yields 2/3 (or 6/11 in the die case). The same coin is being talked about, but the Halfer and Thirder interpretations of SB’s credence refer to different scorecards. Given one scorecard and one payout structure, everyone agrees on the rational betting strategy in normal cases. — Pierre-Normand
I’ll address your extreme case separately, since it appeals to different (nonlinear) subjective utility considerations. — Pierre-Normand
JeffJo
An N-day experiment:
The days of the experiment are named D(1) through D(N).
D(0) is the night before the experiment begins, when SB is informed of all these details before going to sleep.
After she goes to sleep on D(0), an M-sided die will be rolled and preserved throughout out the experiment.
What occurs on each day of the experiment is predetermined using an M-row by N-column calendar. One of M distinct activities (that can all be differentiated from each other), A(1) through A(M), is assigned to each cell in the calendar, such that each appears at least once. The calendar is shown to SB on D(0).
With one variation about A(M) that will be explained below, SB will be awakened each day, and will participate in the activity assigned to that day's column and the row determined by the die roll.
After participating in a day's activity, except A(M), SB will be shown the calendar and asked for her credence in each possible die roll. After any waking activity, she will be put back to sleep with amnesia.
There are three possibilities for the variation:
For A(M), SB will be left asleep all day.
For A(M), SB will be taken to DisneyWorld.
For A(M), SB will be left asleep with probability 0<Q<1 or else taken to DisneyWorld. — JeffJo
Michael
JeffJo
You can't rule out that today is Monday or that today is Tuesday before playing either tennis or football, which is why your example is a false analogy. — Michael
Michael
JeffJo
If she is interviewed before playing football her credence that the coin landed on tails is not 1, but if she is interviewed after playing football her credence that the coin landed on tails is 1.
Playing football is additional information, but nothing like that is available in the traditional problem, and so your example is a false analogy. — Michael
Michael
JeffJo
It's a false analogy because "not being woken up" is nothing like "playing football". It's a mistake to consider "Heads + Tuesday" at all. We can simplify the experiment as such: — Michael
Michael
Michael
Pierre-Normand
Although the ratio is correct, the actual values are very wrong. — Michael
The mistake I think you continue to make is to conflate "the expected return if I always bet on Tails is twice the expected return if I always bet on Heads" and "my credence that the coin landed on Tails/that this is a Tails awakening is twice my credence that the coin landed on Heads/that this is a Heads awakening".
Get involved in philosophical discussions about knowledge, truth, language, consciousness, science, politics, religion, logic and mathematics, art, history, and lots more. No ads, no clutter, and very little agreement — just fascinating conversations.