shminux comments on Many Weak Arguments vs. One Relatively Strong Argument - Less Wrong

20 Post author: JonahSinick 04 June 2013 03:32AM

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Comment author: shminux 04 June 2013 08:51:00PM 3 points [-]

Experts are apparently known to be not much better than amateurs outside of their area of expertise, so whatever Penrose claims about something other than General Relativity and High-energy Physics should have the same weight as that of, say, a grad student in the relevant area, at best. Especially given that he does not have a track record of being proven right in unrelated fields. Thus the argument that

Penrose is one of the greatest physicists of the second half of the 20th century

should have no bearing on taking his claims in neuroscience seriously.

Comment author: JonahSinick 04 June 2013 09:28:26PM 1 point [-]

This is the core point of disagreement. The point is that "Experts are apparently known to be not much better than amateurs outside of their area of expertise" might be wrong (just as all of the other arguments against the truth of his beliefs might be wrong).

Comment author: wedrifid 05 June 2013 04:51:03AM 1 point [-]

This is the core point of disagreement. The point is that "Experts are apparently known to be not much better than amateurs outside of their area of expertise" might be wrong (just as all of the other arguments against the truth of his beliefs might be wrong).

That could be wrong but it is overwhelmingly unlikely to be. If the "core point of disagreement" is that one can freely ignore established science if convenient then the core point is somewhat lacking.

Comment author: JonahSinick 05 June 2013 06:13:55AM 2 points [-]

That could be wrong but it is overwhelmingly unlikely to be.

Why do you think this?

Comment author: wedrifid 05 June 2013 02:19:23PM *  -2 points [-]

Why do you think this?

People did science. I read textbooks.

This is not a complicated or ambiguous question.

Comment author: JoshuaZ 05 June 2013 02:49:56PM *  2 points [-]

Note that there's some evidence that in some fields, experts are actually better outside their own field. This is discussed with relevant studies in Tetlock's "Expert Political Judgement." However, this is for predictions of the future, not judgments about correctness of basic models in their field.

Comment author: [deleted] 05 June 2013 05:42:01PM 5 points [-]

That's interesting, because:

"In this age of academic hyperspecialization, there is no reason for supposing that contributors to top journals--distinguished political scientists, area study specialists, economists, and so on--are any better than journalists or attentive readers of the New York Times in "reading" emerging situations. The data reported in chapters 2, 3, and 4 underscore this point. The analytical skills undergirding academic acclaim conferred no advantage in forecasting and belief-updating exercises." (p. 233)

Comment author: JoshuaZ 05 June 2013 06:25:21PM 1 point [-]

Sorry, bad phrasing on my part. Tetlock's work shows that experts are better outsider their own field compared to their own field, not necessarily compared to other people.

Comment author: [deleted] 05 June 2013 06:47:29PM 1 point [-]

I suspect your phrasing is still bad, because I don't recall anything of the sort in the book.

Comment author: JoshuaZ 05 June 2013 07:33:38PM 1 point [-]

I'm pretty sure that's what I meant to say. Unfortunately, I don't have my copy of the book off-hand. I'll have to get back to you.

Comment author: [deleted] 04 June 2013 11:46:36PM *  0 points [-]

Suppose:

P(penrose says | consciousness & expertise is general) = 0.5
P(penrose says | ~consiousness & expertise is general) = 0

ie. if expertise is general, penrose's opinion is infinitely strong evidence.

P(penrose says | consc & expertise is narrow) = 0.5
P(penrose says | ~ consc & expertise is narrow) = 0.25

ie. if expertise is narrow, penrose's opinion is weak evidence.

Then suppose 90% chance that expertise is general. ie. We are somehow quite sure that experts are never wrong. (quite sure that the argument that expertise is narrow is wrong)

Then:

P(penrose says | consc) = 0.5
P(penrose says | ~consc) = ~0.025

ie. even under these extremely charitable assumptions, Penrose's opinion is only 20x (medium) evidence.

Your assumptions are much more reasonable than I have used here, and will give you correspondingly weaker evidence.

And then, why privilege penrose over the ~1e3 experts who disagree with him?

EDIT: If I were charitable, then I'd note that this argument applies to all arguments, including those on the other side; that strong evidence is in general quite hard to find unless you are very sure of your experimental apparatus.

Comment author: Vaniver 05 June 2013 12:16:45AM *  1 point [-]

And then, why privilege penrose over the ~1e3 experts who disagree with him?

It is valuable to have a list of "people who believe X" and "people who believe ~X," and one might suspect that, if X, the majority position, is incorrect, the people on the ~X list to disproportionately be higher quality. I'm not a good enough science historian to know if that's the case historically, especially because you would want to use contemporary measurements of quality, as many people who believed ~X and it turned out to be right are more highly estimated by hindsight.

(More broadly, there may be systematic patterns to public support on scientific controversies, such that 1) one shouldn't compare length of lists or treat positions of individuals as giving completely independent evidence and 2) there may be patterns that suggest known kinds of events.)