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Dpar comments on Your Strength as a Rationalist - Less Wrong

69 Post author: Eliezer_Yudkowsky 11 August 2007 12:21AM

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Comment author: Dpar 09 August 2010 07:19:32PM *  0 points [-]

"This doesn't remotely follow and is far weaker evidence than other available sources. For a start, everyone knows that you get to Oz with tornadoes and concussions."

Let's not get bogged down in the specific procedure of getting to Oz. My point was that if you truly adapt merely seeing something written somewhere as your standard for evidence, you commit yourself to analyzing and weighing the merits of EVERYTHING you read about EVERYWHERE. Do you mean to tell that when you read a fairy tale you truly consider whether or not what's written there is true? That you don't just dismiss it offhand without giving it a second thought?

"It makes you look like an outsider who isn't able to follow simple social conventions and may have a tendency towards obstinacy. (Since you asked...)"

Like I said above to Vladimir, it's not a big deal, but you're reading quite a bit into a simple habit.

Comment author: Vladimir_Nesov 09 August 2010 07:29:03PM 2 points [-]

The fact that something is really written is true; whether it implies that the written statements themselves are true is a separate theoretical question. Yes, ideally you'd want to take into account everything you observe in order to form an accurate idea of future expected events (observable or not). Of course, it's not quite possible, but not for the want of motivation.

Comment author: Dpar 09 August 2010 07:36:30PM 0 points [-]

Well I didn't think I needed to clarify that I'm not questioning whether or not something that's written is really written. Of course, I'm questioning the truthfulness of the actual statement.

Or not so much it's truthfulness, but rather whether or not it can be considered evidence. Though I realize that you take issue with arguing over word definitions, to me the word evidence has certain meaning that goes beyond every random written sentence, whisper or rumor that you encounter.

Comment author: Vladimir_Nesov 09 August 2010 07:39:17PM *  3 points [-]

The fact that something is written, or not written, is evidence about the way world is, and hence to some extent evidence about any hypothesis about the world. Whether it's strong evidence about a given hypothesis is a different question, and whether the statement written/not written is correct is yet another question.

(See also the links from this page.)

Comment author: Cyan 09 August 2010 07:43:10PM *  6 points [-]

Though I realize that you take issue with arguing over word definitions, to me the word evidence has certain meaning that goes beyond every random written sentence, whisper or rumor that you encounter.

Around these parts, a claim that B is evidence for A is a taken to be equivalent to claiming that B is more probable if A is true than if not-A is true. Something can be negligible evidence without being strictly zero evidence, as in your example of a fairy story.

Comment author: jimrandomh 09 August 2010 07:39:10PM *  7 points [-]

Let's not get bogged down in the specific procedure of getting to Oz. My point was that if you truly adapt merely seeing something written somewhere as your standard for evidence, you commit yourself to analyzing and weighing the merits of EVERYTHING you read about EVERYWHERE.

No, you can acknowledge that something is evidence while also believing that it's arbitrarily weak. Let's not confuse the practical question of how strong evidence has to be before it becomes worth the effort to use it ("standard of evidence") with the epistemic question of what things are evidence at all. Something being written down, even in a fairy tale, is evidence for its truth; it's just many orders of magnitude short of the evidential strength necessary for us to consider it likely.

Comment author: Dpar 09 August 2010 07:53:50PM 0 points [-]

Vladimir, Cyan, and jimrandomh, since you essentially said the same thing, consider this reply to be addressed to all three of you.

Answer me honestly, when reading a fairy tale, do you really stop to consider what's written there, qualify its worth as evidence, and compare it to everything else you know that might contradict it, before making the decision that the probability of the fairy tale being true is extremely low? Do you really not just dismiss it offhand as not true without a second thought?

Comment author: Cyan 09 August 2010 07:58:18PM *  3 points [-]

When I pick up a work of fiction, I do not spend time assessing its veracity. If I read a book of equally fantastic claims which purports to be true, I do spend a little time. You might want to peruse bounded rationality for an overview.

Comment author: Dpar 09 August 2010 08:02:14PM -1 points [-]

So you would then agree that merely the fact that something is written SOMEWHERE, does not automatically qualify it as evidence?

(Incidentally that is my original point, which in spite of seeming as common sense as common sense can be, has attracted a surprising amount of disagreement.)

Comment author: Cyan 09 August 2010 08:07:04PM *  5 points [-]

So you would then agree that merely the fact that something is written SOMEWHERE, does not automatically qualify it as evidence?

You have to specify what it purports to be evidence of before I can give you an answer that isn't a tangent.

Edited to add: Maybe I can do better than the above sentence. I affirm that the existence of this book is negligible but not strictly zero evidence for the claims detailed therein.

Comment author: Unknowns 09 August 2010 08:12:18PM 3 points [-]

There may be sense in which this is common sense, but you were purposely using it tendentiously, which is why people responded in the technical way that they did.

Eliezer said that he read something "somewhere", obviously intending to say that he read it somewhere that he considered trustworthy at the time, not in a fairy tale.

Comment author: Dpar 09 August 2010 08:56:39PM 0 points [-]

Well, what can I say? I simply don't consider the vague recollection of reading something somewhere credible evidence of anything, and I stand by that. However, the amount of people that took issue with this statement did open my eyes to the fact that the definition of word "evidence" is not as clear cut as I thought it to be. Not sure if there's any way to resolve this difference of opinion though.

Comment author: WrongBot 09 August 2010 09:00:34PM 5 points [-]

The easy solution is to stop arguing about the definition of evidence. This community uses it to mean one thing, you're using it to mean something else, and any sort of conflict goes away as soon as people make clear which definition they're using. Since this community already has an accepted definition, you would be safe in assuming that that definition is what other posters here have in mind when they use the word "evidence". By the same token, you should probably find a more precise way to refer to the definition of evidence that you are using in order to avoid being misinterpreted.

Comment author: jimrandomh 09 August 2010 09:13:03PM 3 points [-]

Sticking an adjective in front of the word evidence seems to work. "Evidence" includes things that give you 10^-15 bits of information; on the other hand "good evidence", "usable evidence" and "credible evidence" all imply that the strength of the evidence is at least not exponentially tiny.

Comment author: SilasBarta 09 August 2010 10:01:28PM *  1 point [-]

I thought that "evidence", unmodified, would mean non-trivial evidence; otherwise, everything has to count as evidence because it will have some connection to the hypothesis, however weak. To specify a kind of evidence that includes the 1e-15 bit case, I think you would need to say "weak evidence" or "very weak evidence".

But I'm not the authority on this: How do others here interpret the term "evidence" (in the Bayesian sense) when it's unmodified?

Comment author: Dpar 09 August 2010 09:18:58PM 0 points [-]

That's fair enough. However, judging by what I've read, this community's definition of evidence seems to constitute just about anything ever written about anything. How would you then differentiate evidence, from rumor, hearsay, speculation, etc.?

Comment author: WrongBot 09 August 2010 09:21:50PM 4 points [-]

The wiki should be a good starting point for answering this question. What is Evidence? may also be helpful.

Short version: rumor, hearsay, and speculation are evidence, albeit of a very weak variety.

Comment author: Vladimir_Nesov 09 August 2010 09:24:09PM 2 points [-]

Rumor, hearsay, etc. falls under our definition of evidence, just weak evidence, or probably very indirect (for example, if there is a rumor that A, it might constitute evidence against A being true, given other things you know).

Comment author: thomblake 09 August 2010 09:34:04PM 5 points [-]

credible evidence

As noted by jimrandomh, saying 'credible evidence' does make an effort to differentiate between different sorts of evidence. If your claim was simply that reading something was not evidence, then you should not have to qualify the word when you use it now. I imagine for those of us who seem to be disagreeing with you, we would agree that that does not constitute 'credible evidence' for some values of 'credible'.

Comment author: Dpar 09 August 2010 09:48:21PM *  5 points [-]

That's really clever. I always thought that "credible evidence" was a bit redundant actually. I just used as a figure of speech without thinking about, but according to my definition of evidence that it has to be credible is pretty much implicit. It has been made abundantly clear to me, however, that this community's definition differs substantially, so that's the definition I will use when posting here going forward.

Comment author: Oligopsony 09 August 2010 08:00:05PM 3 points [-]

No, but only because that would be cognitively burdensome. We're boundedly rational.

Comment author: Vladimir_Nesov 09 August 2010 08:11:46PM 2 points [-]

Immediate observation is only that something is written. That it's also true is a theoretical hypothesis about that immediate observation. That what you are reading is a fairy tale is evidence against the things written there being true, so the theory that what's written in a fairy tale is true is weak. On the other hand, the fact that you observe the words of a given fairy tale is strong evidence that the person (author) whose name is printed on the cover really existed.

Comment author: Dpar 09 August 2010 08:47:35PM -2 points [-]

All that is indisputably true. But you didn't really answer my question on whether or not you give enough consideration to what's written in a fairy tale (not whether or not it's written, not who it's written by, but the actual claims made therein) to truly consider it evidence to be incorporated into or excluded from your model of the world.

Comment author: Vladimir_Nesov 09 August 2010 09:09:28PM *  2 points [-]

Evidence isn't usually something you "include" in your model of the world, it's something you use to categorize models of the world into correct and incorrect ones. Evidence is usually something not interesting in itself, but interesting instrumentally because of the things it's connected to (caused by).

Comment author: wedrifid 10 August 2010 08:21:59AM 1 point [-]

But you didn't really answer my question on whether or not you give enough consideration to what's written in a fairy tale (not whether or not it's written, not who it's written by, but the actual claims made therein) to truly consider it evidence to be incorporated into or excluded from your model of the world.

That is because it is a bad question and one of a form for which you have already received responses.

Comment deleted 10 August 2010 08:18:14AM [-]
Comment author: Dpar 10 August 2010 12:35:58PM -2 points [-]

Duly noted. God forbid I do something that annoys you. Won't be able to live with myself.

Comment author: ciphergoth 10 August 2010 12:41:33PM 6 points [-]

As always, I recommend against sarcasm, which can hide errors in reasoning that would be more obvious when you speak straightforwardly.

Comment author: Dpar 10 August 2010 01:16:17PM -2 points [-]

It was a comment on wedrifid's implicit assumption that I should care about what annoys him and bizarre expectation that I would adjust my behavior because I was "prompted" (not asked politely mind you) by him. Not sure what part of that is not obvious to you.

Comment author: JoshuaZ 10 August 2010 01:25:13PM 5 points [-]

Generally, when some minor formatting issue annoys a long-standing member of an internet community it is a good idea to listen to what they have to say. Many internet fora have standard rules about formatting and style that aren't explicitly expressed. These rules are convenient because they make reading easier for everyone. There's also a status/signaling aspect in that not using standard formatting signals someone is an outsider. Refusing to adopt standard format and styling signals an implicit lack of identification with a community. Even if one doesn't identify with a group, the effort it takes to conform to formatting norms is generally small enough that the overall gain is positive.

Comment author: Dpar 11 August 2010 11:55:52AM 2 points [-]

You're absolutely right. I have no problem using indentation for quotes, as a matter of fact I was wondering how to do that, it's his condescending tone that I took issue with. In retrospect though, I should have just ignored it, but let my temper get the best of me. I'll try to keep counter-productive comments to a minimum in the future.

Comment author: RobinZ 11 August 2010 10:08:59PM 0 points [-]

Indentation happens by putting a greater-than sign at the beginning of the line. Thus:

> The quick brown fox jumps over the lazy dog.

becomes

The quick brown fox jumps over the lazy dog.