# jessicata comments on Why Two Valid Answers Approach is not Enough for Sleeping Beauty

• halfers have to condition on there being at least one observer in the possible world. if the coin can come up 0,1,2 at 13 each, and Sleeping Beauty wakes up that number of times, halfers still think the 0 outcome is 0% likely upon waking up.

• halfers also have to construct the reference class carefully. if there are many events of people with amnesia waking up once or twice, and SSA’s reference class consists of the set of awakenings from these, then SSA and SIA will agree on a 13 probability. this is because in a large population, about 13 of awakenings are in worlds where the coin came up such that there would be one awakening.

• halfers also have to construct the reference class carefully. if there are many events of people with amnesia waking up once or twice, and SSA’s reference class consists of the set of awakenings from these, then SSA and SIA will agree on a 13 probability.

This is a good example of what I meant by

The discourse went for so long and accumulated so much confusion in process, that it requires much more direct attention.

You don’t need to think about SSA, SIA to solve the Sleeping Beauty problem at all.

All you need is to construct an appropriate probability space and use basic probability theory instead of inventing clever reasons why it doesn’t apply in this particular case. But people failed to correctly model the problem and then started generalizing their failed approaches as a great opportunity to write more philosophy papers and so here we are, seriously talking about how participation in a Sleeping Beauty experiment should give you an ability to switch bodies.

if the coin can come up 0,1,2 at 13 each, and Sleeping Beauty wakes up that number of times, halfers still think the 0 outcome is 0% likely upon waking up.

Am I missing something? How is it at all controversial? If by design of the experiment event E doesn’t happen when random number generator produces outcome O, then you observe event E happening, you lawfully update in favor of outcome O not happening.

• All you need is to construct an appropriate probability space and use basic probability theory instead of inventing clever reasons why it doesn’t apply in this particular case.

I don’t see how to do that but maybe your plan is to get to that at some point

Am I missing something? How is it at all controversial?

it’s not, it’s just a modification on the usual halfer argument that “you don’t learn anything upon waking up”

• I don’t see how to do that but maybe your plan is to get to that at some point

Yep, that’s exactly what I’m going to do in the post after the next one.

it’s not, it’s just a modification on the usual halfer argument that “you don’t learn anything upon waking up”

Isn’t it obvious, that the correct interpretation of “you don’t learn anything upon making up” is not about all possible settings where going to sleep and waking up happens, but about type of settings where some event happens on every outcome? That it’s just about conservation of expected evidence? If the random generator produces outcomes O1, O2, … On and on every outcome event E always happens then observation of event E doesn’t allow to distinguish between any of the outcomes of random number generator.