what interpretation of the word “probability” does allow you to think that the probability of something is 1 and then change to something other than 1?
Any interpretation where you can fix a broken model. I can imagine a conversation like this...
Prankster: I’m holding a die behind my back. If I roll it, what probability would you assign to a 1 coming up?
cupholder: Is it loaded?
Prankster: No.
cupholder: Are you throwing it in a funny way, like in one of those machines that throws it so it’s really likely to come up a 6 or something?
Prankster: No, no funny tricks here. Just rolling it normally.
cupholder: Then you’ve got a 1⁄6 probability of rolling a 1.
Prankster: And what about rolling a 2?
cupholder: Well, the same.
Prankster: And so on for all the other numbers, right?
cupholder: Sure.
Prankster: So you assign a probability of 1 to a number between 1 and 6 coming up?
cupholder: Yeah.
Prankster: Surprise! It’s 20-sided!
cupholder: Huh. I’d better change my estimate from 1 to 6⁄20.
Any interpretation where you can fix a broken model. I can imagine a conversation like this...
Prankster: I’m holding a die behind my back. If I roll it, what probability would you assign to a 1 coming up?
cupholder: Is it loaded?
Prankster: No.
cupholder: Are you throwing it in a funny way, like in one of those machines that throws it so it’s really likely to come up a 6 or something?
Prankster: No, no funny tricks here. Just rolling it normally.
cupholder: Then you’ve got a 1⁄6 probability of rolling a 1.
Prankster: And what about rolling a 2?
cupholder: Well, the same.
Prankster: And so on for all the other numbers, right?
cupholder: Sure.
Prankster: So you assign a probability of 1 to a number between 1 and 6 coming up?
cupholder: Yeah.
Prankster: Surprise! It’s 20-sided!
cupholder: Huh. I’d better change my estimate from 1 to 6⁄20.