SIA is just Bayesian updating on the fact that you exist; this is the same update that an outside observer would make, if informed of your existence.
Actually, It also assumes the outside observer learns of your existence by a certain process. E.g. by randomly sampling all potentially existing observers (in a reference class) and finds you. (If on the contrary, the outsider learns about your existence by sampling all actual observers then the update would follow SSA.) Of course, if the outsider defines the reference class by all the definable characteristics of you then he would effectively get a reference class of one. But it seems dubious why would an outsider pay attention to this particular set of characteristics in the first place.
SIA is the Bayesian update on knowing your existence (ie if they were always going to ask if dadadarren existed, and get a yes or no answer). The other effects come from issues like “how did they learn of your existence, and what else could they have learnt instead?” This often does change the impact of learning facts, but that’s not a specifically anthropics problem.
SIA is the Bayesian update on knowing your existence (ie if they were always going to ask if dadadarren existed, and get a yes or no answer)
The i.e. part is what I was trying to point, thus I agree with this assessment. So the anthropic debate can be presented as whether I should give the same probability as some outsider learns of my existence by this process. SIA suggests yes. Halfers in general suggest no.
Here SIA has the advantage of not going to generate any disagreement when the outsider and I can communicate. We would give the same probability values. Whereas all halfers (not just SSA supporters) must find a way to explain why the outsider and I must give different probabilities even when we share all information. i.e. what aspect of the problem is incommunicable.
Actually, It also assumes the outside observer learns of your existence by a certain process. E.g. by randomly sampling all potentially existing observers (in a reference class) and finds you. (If on the contrary, the outsider learns about your existence by sampling all actual observers then the update would follow SSA.) Of course, if the outsider defines the reference class by all the definable characteristics of you then he would effectively get a reference class of one. But it seems dubious why would an outsider pay attention to this particular set of characteristics in the first place.
SIA is the Bayesian update on knowing your existence (ie if they were always going to ask if dadadarren existed, and get a yes or no answer). The other effects come from issues like “how did they learn of your existence, and what else could they have learnt instead?” This often does change the impact of learning facts, but that’s not a specifically anthropics problem.
The i.e. part is what I was trying to point, thus I agree with this assessment. So the anthropic debate can be presented as whether I should give the same probability as some outsider learns of my existence by this process. SIA suggests yes. Halfers in general suggest no.
Here SIA has the advantage of not going to generate any disagreement when the outsider and I can communicate. We would give the same probability values. Whereas all halfers (not just SSA supporters) must find a way to explain why the outsider and I must give different probabilities even when we share all information. i.e. what aspect of the problem is incommunicable.
Ah, understood. And I think I agree.