Well, in the particular case he posed with a prior of 0.9 on the 1d12, 2 pieces of information are also useless. In fact, you need 4 pieces of paper to have nonzero value of information (and even then, I think the expected value of the 4 is < £1).
Sure, but I don’t see where that changes the analysis. The probability of you getting 4 pieces of information, contingent on getting the first one, has got to be larger than the probability of getting 4, contingent on not getting the first one. (In fact the latter seems to be a contradiction, which presumably has probability zero.) So the first one still has some value, even if it’s perhaps rather smaller than the value of the time it takes to do the formal calculation of the value.
You’re right. This seems like an interesting exercise in programming, actually: build a tool that tells you the VOI of a certain number of guesses. I know 0-3 have an EV of 0, but when I try to plug in 4, I realize why a recursive function might have been a bad idea.
Well, in the particular case he posed with a prior of 0.9 on the 1d12, 2 pieces of information are also useless. In fact, you need 4 pieces of paper to have nonzero value of information (and even then, I think the expected value of the 4 is < £1).
Sure, but I don’t see where that changes the analysis. The probability of you getting 4 pieces of information, contingent on getting the first one, has got to be larger than the probability of getting 4, contingent on not getting the first one. (In fact the latter seems to be a contradiction, which presumably has probability zero.) So the first one still has some value, even if it’s perhaps rather smaller than the value of the time it takes to do the formal calculation of the value.
You’re right. This seems like an interesting exercise in programming, actually: build a tool that tells you the VOI of a certain number of guesses. I know 0-3 have an EV of 0, but when I try to plug in 4, I realize why a recursive function might have been a bad idea.