The notion of a broken clock being sometimes right is based on a gross misunderstanding of what information is.

A clock that always shows the same time is never right, even in the moments of the day when the time happens to be what it shows, because you don't gain any information about what time it is by looking at the clock.

This reasoning also applies to chatbots. If you can't tell whether what you have been given is useful information unless you alreay know the information, then you haven't been given useful information.

@riley Hmmm. I think you got that one wrong. The point of the figure of speech is not to give credit to the clock. The point is to point out that the information is useless.

@proedie No, that's not how information works. Information is about reducing your uncertainty space. Every time you can exclude half of the uncertainty space, you will have gained one bit of information. If you exclude less than half of the uncertainty space, you will have gained less than a bit of information. Just ask Claude[1].

Looking at broken clock[2] does not reduce your uncertainty space at all, therefore you gain zero bits of information. The classic formula Claude Shannon is famous for involves dividing the volume of the uncertainty space after gaining information with the volume of the uncertainty space before gaining information, and then taking a base-2 logarithm of the ratio and negating it. If you don't care a minus one bit about negative amounts of data, you can turn the ratio on its top; then, negation won't be necessary. But there's didactic reasons for presenting it in the classic way.

[1] Claude Shannon, an overall smart human and a measurer of the enthropy of information. Who were you thinking about?
[2] Well, there's the minor issue of knowing that the clock is broken, lest you erroneously throw out parts of your uncertainty space that might actually be valid. But the problem of information-resembling text is also an issue that applies to chatbots.

@riley That’s the point. You got information theory right. You just misunderstood the expression with the clock.

When I say: ‘My AI gave me a correct answer once’, you can reply: ‘Sure, even a broken clock is correct twice a day.’ Thus stressing that coincidental correctness is worthless.

@proedie @riley given a cursory googling and this reddit poll, it doesn't seem like the meaning is that clear to the average person

https://www.reddit.com/r/polls/comments/1brhoj4/how_do_you_interpret_the_saying_a_broken_clock_is/

@proedie @riley after obsessing a little over getting to the bottom of this, the answer seems to be that the historical origin (from 1711) is akin to "If you stop chasing trends you will sometimes be fashionable", which is more in line with riley's definition in the OP. The other "official" definitions I've found seem to follow this as well.

The definition that "coincidental correctness is worthless" seems to be a personal (though common) interpretation.

@jonoleth @riley Oh, wow. Could you share the source with us?

@proedie Sounds like something that friends of Beau Brummell might have noticed, but he lived too late for that.

@jonoleth