You're looking at Less Wrong's discussion board. This includes all posts, including those that haven't been promoted to the front page yet. For more information, see About Less Wrong.

lessdazed comments on Take heed, for it is a trap - Less Wrong Discussion

47 Post author: Zed 14 August 2011 10:23AM

You are viewing a comment permalink. View the original post to see all comments and the full post content.

Article Navigation

Comments (187)

Sort By: Best

You are viewing a single comment's thread. Show more comments above.

Comment author: komponisto 16 August 2011 01:53:15AM 5 points [-]

Any statement for which you have the faintest idea of its truth conditions will be specified in sufficient detail that you can count the bits, or count the symbols...If you start with 0 bits the problem is just underspecified.

What a perfect illustration of what I was talking about when I wrote:

Of course, we almost never reach this level of ignorance in practice, which makes this the type of abstract academic point that people all-too-characteristically have trouble with. The step of calculating the complexity of a hypothesis seems "automatic", so much so that it's easy to forget that there is a step there.

You can call 0 bits "underspecifed" if you like, but the antilogarithm of 0 is still 1, and odds of 1 still corresponds to 50% probability.

Given your preceding comment, I realize you have a high prior on people making simple errors. And, at the very least, this is a perfect illustration of why never to use the "50%" line on a non-initiate: even Yudkowsky won't realize you're saying something sophisticated and true rather than banal and false.

Nevertheless, that doesn't change the fact that knowing the complexity of a statement is knowing something about the statement (and hence not being in total ignorance).

Comment author: lessdazed 16 August 2011 03:31:51AM -2 points [-]

Knowing that a statement is a proposition is far from being in total ignorance.

Writing about propositions using the word "statements" and then correcting people who say you are wrong based on true things they say about actual statements would be annoying. Please make it clear you aren't doing that.

Comment author: komponisto 16 August 2011 04:41:04AM 0 points [-]

Neither the grandparent nor (so far as I can tell) the great-grandparent makes the distinction between "statements" and "propositions" that you have drawn elsewhere. I used the term "statement" because that was what was used in the great-grandparent (just as I used it in my other comment because it was used in the post). Feel free to mentally substitute "proposition" if that is what you prefer.

Comment author: lessdazed comment score below threshold [+] (8 children)

Comment author: komponisto 16 August 2011 06:27:13AM 2 points [-]

My previous comment should have sufficed to communicate to you that I do not regard the distinction you are making as relevant to the present discussion. It should be amply clear by this point that I am exclusively concerned with things-that-must-be-either-true-or-false, and that calling attention to a separate class of utterances that do not have truth-values (and therefore do not have probabilities assigned to them) is not an interesting thing to do in this context. Downvoted for failure to take a hint.

Comment author: lessdazed comment score below threshold [+] (6 children)

Comment author: lessdazed 16 August 2011 06:56:07AM * -3 points [-]

It should be amply clear by this point that I am exclusively concerned with things-that-must-be-either-true-or-false

Then when Eliezer says:

Any statement for which you have the faintest idea of its truth conditions will be specified in sufficient detail that you can count the bits, or count the symbols, and that's where the rough measure of prior probability starts - not at 50%.

you shouldn't say:

Given your preceding comment, I realize you have a high prior on people making simple errors. And, at the very least, this is a perfect illustration of why never to use the "50%" line on a non-initiate: even Yudkowsky won't realize you're saying something sophisticated and true rather than banal and false.

as a response to Eliezer making true statements about statements and not playing along with OP's possible special definition of "statement". If when Eliezer read "statement", he'd interpreted it as "proposition", he might be unreasonable in inferring there was an error, but he didn't, so he wasn't. So you shouldn't implicitly call him out as having made a simple error.

As far as "even Yudkowsky won't realize you're saying something sophisticated and true rather than banal and false" goes, no one can read minds. It is possible the OP meant to convey actual perfect understanding with the inaccurate language he used. Likewise for "Not just low-status like believing in a deity, but majorly low status," assuming idiosyncratic enough meaning.

calling attention to a separate class of utterances that do not have truth-values (and therefore do not have probabilities assigned to them) is not an interesting thing to do in this context.

I'm calling attention to a class that contains all propositions as well as other things. Probabilities may be assigned to statements being true even if they are actually false, or neither true nor false. If a statement is specified to be a proposition, you have information such that a bare 50% won't do.

Comment author: komponisto 16 August 2011 08:49:14AM * 3 points [-]

Where did you get the idea that "statement" in Eliezer's comment is to be understood in your idiosyncratic sense of "utterances that may or may not be 'propositions'"? Not only do I dispute this, I explicitly did so earlier when I wrote (emphasis added):

Neither the grandparent nor (so far as I can tell) the great-grandparent makes the distinction between "statements" and "propositions" that you have drawn elsewhere.

Indeed, it is manifestly clear from this sentence in his comment:

it's questionable whether you can even call that a statement, since you can't say anything about its truth-conditions.

that Eliezer means by "statement" what you have insisted on calling a "proposition": something with truth-conditions, i.e. which is capable of assuming a truth-value. I, in turn, simply followed this usage in my reply. I have never had the slightest interest in entering a sub-discussion about whether this is a good choice of terminology. Furthermore, I deny the following:

Probabilities may be assigned to [statements/propositions/what-the-heck-ever] being true even if they are...neither true nor false.

and, indeed, regard the falsity of that claim as a basic background assumption upon which my entire discussion was premised.

Perhaps it would make things clearer if the linguistic terminology ("statement", "proposition", etc) were abandoned altogether (being really inappropriate to begin with), in favor of the term "hypothesis". I can then state my position in (hopefully) unambiguous terms: all hypotheses are either true or false (otherwise they are not hypotheses), hypotheses are the only entities to which probabilities may be assigned, and a Bayesian with literally zero information about whether a hypothesis is true or false must assign it a probability of 50% -- the last point being an abstract technicality that seldom if ever needs to be mentioned explicitly, lest it cause confusion of the sort we have been seeing here (so that Bayesian Bob indeed made a mistake by saying it, although I am impressed with Zed for having him say it).

Make sense now?

Comment author: ArisKatsaris 16 August 2011 12:54:27PM 1 point [-]

and a Bayesian with literally zero information about whether a hypothesis is true or false must assign it a probability of 50%

You can state it better like this: "A Bayesian with literally zero information about the hypothesis."

"Zero information about whether a hypothesis is true or false" implies that we know the hypothesis, and we just don't know whether it's a member in the set of true propositions.

"Zero information about the hypothesis" indicates what you really seem to want to say -- that we don't know anything about this hypothesis; not its content, not its length, not even who made the hypothesis, or how it came to our attention.

Comment author: lessdazed 17 August 2011 09:00:37PM -1 points [-]

we don't know...how it came to our attention

I don't see how this can make sense in one sense. If we don't know exactly how it came to our attention, we know that it didn't come to our attention in a way that stuck with us, so that is some information we have about how it came to our attention - we know some ways that it didn't come to our attention.

Comment author: ArisKatsaris 20 August 2011 05:43:50PM 0 points [-]

You're thinking of human minds. But perhaps we're talking about a computer that knows it's trying to determine the truth-value of a proposition, but the history of how the proposition got inputted into it got deleted from its memory; or perhaps it was designed to never holds that history in the first place.

continue this thread »

Comment author: lessdazed comment score below threshold [+] (0 children)

lessdazed comments on Take heed, for it is a trap - Less Wrong Discussion

Article Navigation

Comments (187)

Nearest Meetups

Virtual Study Room

Recent Comments

Recent Posts

Recent Open Threads

Recent Rationality Diaries

Recent Wiki Edits

Top Contributors, 30 Days

Recent Karma Awards

Comments (187)

Top Contributors, 30 Days

You'll need to login or register to do that

(Don't worry, it only takes a few seconds)

Create

Login