It’s possible to be, to some extent, certain that you haven’t thought of a correct answer (if not certain you don’t know the answer), because you don’t have any answer in mind and yet are not considering the answer “this is a trick question” or “there is no correct answer”. Is this something that should be represented, making “0%” correct to include, or am I confused?
I got one blank question, which I think was an error with loading since the answer came up the same as the previous question, and the one after it took a couple seconds to appear on-screen.
I’d prefer not to allow 0 and 1 as available credences. But if 0 remained as an option I would just interpret it as “very close to 0” and then keep using the app, though if a future version of the app showed me my Bayes score then the difference between what the app allows me to choose (0%) and what I’m interpreting 0 to mean (“very close to 0″) could matter.
I think it’s misleading to just drop in the statement that 0 and 1 are not probabilities.
There is a reasonable and arguably better definition of probabilities which excludes them, but it’s not the standard one, and it also has costs—for example probabilities are a useful tool in building models, and it is sometimes useful to use probabilities 0 and 1 in models.
(aside: it works as a kind of ‘clickbait’ in the original article title, and Eliezer doesn’t actually make such a controversial statement in the post, so I’m not complaining about that)
Fair enough. I’ve edited my original comment.
(For posterity: the text for my original comment’s first hyperlink originally read “0 and 1 are not probabilities”.)