06-07-2025, 10:35 PM
(06-07-2025, 05:33 PM)Mauro wrote: You are not allowed to view links. Register or Login to view.To apply Bayes one does not need a prior probability at all. Indeed, discriminating between prior and evidence is ihmo unnecessary and misleading. Start from a condition of absolutely zero knowledge, that is to say P(H) = 0.5 and P(notH) = 0.5 This is the only 'prior' one needs, and it's trivial.
But that is not "no prior", it is "prior prob of hoax = 0.5".
We would have absolutely zero knowledge if hypothesis H was "the Hraxx is a foobar" and we have no idea of what those terms mean. But even then, if the other party tells us that "note that, if it is not a foobar, it must be either a quxqux or a blooop", then should we set Prob(H) = 1/3?
But we do have a lot of knowledge about the issue. Everything we know about the VMS and its history, manuscripts from that time, the world as it was then, what people knew or could have known, how forgers and their marks would probably think and act... That is what makes each of us have a different prior Prob(H) - namely, the probability we had assigned to H before we knew the information A provided by the T&T paper. That is what must go into Bayes's formula for Prob(H|A).