ChristianKl comments on Rationality Quotes May 2013 - Less Wrong

6 Post author: katydee 03 May 2013 08:02PM

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

Article Navigation

Comments (387)
Tags: quotes

Comments (387)

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

Comment author: [deleted] 02 May 2013 03:48:24AM *  112 points [-]

"The spatial anomaly has interacted with the tachyonic radiation in the nebula, it's interfering with our sensors. It's impossible to get a reading."

"There's no time - we'll have to take the ship straight through it!"

"Captain, I advise against this course of action. I have calculated the odds against our surviving such an action at three thousand, seven hundred and forty-five to one."

"Damn the odds, we've got to try... wait a second. Where, exactly, did you get that number from?"

"I hardly think this is the time for-"

"No. No, fuck you, this is exactly the time. The fate of the galaxy is at stake. Trillions of lives are hanging in the balance. You just pulled four significant digits out of your ass, I want to see you show your goddamn work."

"Well, I used the actuarial data from the past fifty years, relating to known cases of ships passing through nebulae that are interacting with spatial anomalies. There have been approximately two million such incidents reported, with only five hundred and forty-two incidents in which the ship in question survived intact."

"And did you at all take into account that ship building technology has improved over the past fifty years, and that ours is not necessarily an average ship?"

"Indeed I did, Captain. I weighted the cases differently based on how recent they were, and how close the ship in question was in build to our own. For example, one of the incidents with a happy ending was forty-seven years ago, but their ship was a model roughly five times our size. As such, I counted the incident as having twenty-four percent of the relevance of a standard case."

"But what of our ship's moxie? Can you take determination and drive and the human spirit into account?"

"As a matter of fact I can, Captain. In our three-year history together, I have observed that both you and this ship manage to beat the odds with a measurable regularity. To be exact, we tend to succeed twenty-four point five percent more often than the statistics would otherwise indicate - and, in fact, that number jumps to twenty-nine point two percent specifically in cases where I state the odds against our success to three significant digits or greater. I have already taken that supposedly 'unknowable' factor into account with my calculations."

"And you expect me to believe that you've memorized all these case studies and performed this ridiculously complicated calculation in your head within the course of a normal conversation?"

"Yes. With all due respect to your species, I am not human. While I freely admit that you do have greater insight into fields such as emotion, interpersonal relations, and spirituality than I do, in the fields of memory and calculation, I am capable of feats that would be quite simply impossible for you. Furthermore, if I may be perfectly frank, the entire purpose of my presence on the bridge is to provide insights such as these to help facilitate your command decisions. If you're not going to heed my advice, why am I even here?"

"Mm. And we're still sitting at three thousand seven hundred to one against?"

"Three thousand, seven hundred and forty five to one."

"Well, shit. Well, let's go around, then."

The Vulcan your Vulcan could sound like if he wasn't made of straw, I guess? Link

Comment author: ChristianKl 03 May 2013 12:38:47PM *  2 points [-]

"Mm. And we're still sitting at three thousand seven hundred to one against?"

"Three thousand, seven hundred and forty five to one."

You shouldn't trust people who claim to know 4 digits of accuracy for a forcast like this. The uncertainity involved in the calcuation has to be greater.

Comment author: wedrifid 03 May 2013 01:01:43PM 20 points [-]

You shouldn't trust people who claim to know 4 digits of accuracy for a forcast like this.

You shouldn't trust a human person who makes that claim. But if we are using 'person' in a way that includes the steel-Vulcan from the quote then yes, you should.

The uncertainity involved in the calculation has to be greater.

It is all uncertainty. There is no particular reason to doubt the steel-Vulcan's ability to calibrate 'meta' uncertainties too.

In the face of all the other evidence about the relative capabilities of the species in question that the character in question is implied to have it would be an error to overvalue the heuristic "don't trust people who fail to signal humility via truncating calculations". The latter is, after all, merely a convention. Given the downsides of that convention (it inevitably makes predictions worse) it is relatively unlikely that the Vulcans would have the same traditions regarding significant figure expression.

Comment author: Eliezer_Yudkowsky 03 May 2013 08:04:38PM 13 points [-]

And lo, Wedrifid did invent the concept of Steel Vulcan and it was good.

Do we actually have enough fictional examples of this to form a trope? (At least 3, 5 would be better.)

Comment author: ChristianKl 03 May 2013 03:03:18PM 0 points [-]

You shouldn't trust a human person who makes that claim. But if we are using 'person' in a way that includes the steel-Vulcan from the quote then yes, you should.

There inherent uncertainity in the input. The steel-Vulcan in question counted one specifc case as being 24% relevant to the current question. That's two digits of accuracy.

If many of your input variables only have two digits of accuracy the end result shouldn't have four digits of accuracy.

Comment author: DaFranker 03 May 2013 04:31:09PM *  18 points [-]

If many of your input variables only have two digits of accuracy the end result shouldn't have four digits of accuracy.

Almost-inaudibly, whispering in a small corner of the room while scribbling in a notebook that the teacher is totally stupid while said teacher says something similar to the quote above:

under the assumption that all variables have equivalent ratios of weight to the final result and that the probability distribution of the randomness is evenly distributed across sub-digits of inaccuracy, along with a few other invisible assumptions about the nature of the data and calculations

Yep, that's me in high school.

In your example, the cited specific case only means that the final accuracy to be calculated is +- 0.01 individual ship relevance, which means that at the worst this one instance, by the standard half-the-last-significant-digit rule of thumb (which is not by any means an inherent property of uncertainties) means that there's +- 0.5% * 1 ship variance over the 542 : 2 000 000 ratio for this particular error margin.

Note also that "24% weight of the relevance of 1 ship in the odds" translates very poorly in digit-accuracies to "3745 : 1", because 3745:1 is also 0.026695141484249866524292578750667% chance, which is a shitton of digits of accuracy, and is also 111010100001 : 1, which is 12 digits of accuracy, and is also (...) *

As you can see, the "digits of accuracy" heuristic fails extremely hard when you convert between different ways to represent data. Which is exactly what happened several times in the steel-vulcan's calculations.

Moral of the story: Don't work with "digits of accuracy", just memorize your probability distribution functions over uncertainty and maximal variances and integrate all your variables with uncertainty margins and weights during renormalization, like a real Vulcan would.

Edit: * (Oh, and it's also 320 in base-35, so that's exactly two significant digits. Problem solved, move along.)

Comment author: wedrifid 03 May 2013 03:22:41PM *  8 points [-]

If many of your input variables only have two digits of accuracy the end result shouldn't have four digits of accuracy.

That is indeed the (mere, human) convention as taught in high schools of our shared culture. See above regarding the absurdity of using that heuristic as a reason for rejecting the advice of what amounts to a superintelligence.

Comment author: shminux 03 May 2013 03:54:23PM *  6 points [-]

It's not about accuracy, it's about not privileging 3700 over 3745. Neither is a particularly round number in, say, binary, and omitting saying "forty five" after converting this number into decimal system for human consumption is not much of a time saver.

Comment author: [deleted] 04 May 2013 08:22:30AM 0 points [-]

But re-mentioning the “forty five” after a human asks you “three thousand seven hundred?” is mostly pointless nitpicking, and demonstrates a lack of understanding of human (well, at least, of neurotypical human) psychology IMO.

Comment author: TheOtherDave 04 May 2013 05:01:45PM 11 points [-]

Either that, or it reflects an accurate understanding of the things that humans (justifiably or otherwise) treat as signals of authoritative knowledge. I mean, there's a reason people who want to sound like experts quote statistics to absurd levels of precision; rounding off sounds less definitive to most people.

Comment author: DanielLC 07 May 2013 03:59:22AM 6 points [-]

Perhaps, but on the off chance that the captain doesn't listen, giving the exact probability increases the chances of success. The Vulcan mentioned that.

Powered by Reddit Powered by Reddit