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Case study: abuse of frequentist statistics

25 Cyan 21 February 2010 06:35AM

Recently, a colleague was reviewing an article whose key justification rested on some statistics that seemed dodgy to him, so he came to me for advice. (I guess my boss, the resident statistician, was out of his office.) Now, I'm no expert in frequentist statistics. My formal schooling in frequentist statistics comes from my undergraduate chemical engineering curriculum -- I wouldn't rely on it for consulting. But I've been working for someone who is essentially a frequentist for a year and a half, so I've had some hands-on experience. My boss hired me on the strength of my experience with Bayesian statistics, which I taught myself in grad school, and one thing reading the Bayesian literature voraciously will equip you for is critiquing frequentist statistics. So I felt competent enough to take a look.1

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The Correct Contrarian Cluster

39 Eliezer_Yudkowsky 21 December 2009 10:01PM

Followup to: Contrarian Status Catch-22

Suppose you know someone believes that the World Trade Center was rigged with explosives on 9/11.  What else can you infer about them?  Are they more or less likely than average to believe in homeopathy?

I couldn't cite an experiment to verify it, but it seems likely that:

  • There are persistent character traits which contribute to someone being willing to state a contrarian point of view. 
  • All else being equal, if you know that someone advocates one contrarian view, you can infer that they are more likely than average to have other contrarian views.

All sorts of obvious disclaimers can be included here.  Someone who expresses an extreme-left contrarian view is less likely to have an extreme-right contrarian view.  Different character traits may contribute to expressing contrarian views that are counterintuitive vs. low-prestige vs. anti-establishment etcetera.  Nonetheless, it seems likely that you could usefully distinguish a c-factor, a general contrarian factor, in people and beliefs, even though it would break down further on closer examination; there would be a cluster of contrarian people and a cluster of contrarian beliefs, whatever the clusters of the subcluster.

(If you perform a statistical analysis of contrarian ideas and you find that they form distinct subclusters of ideologies that don't correlate with each other, then I'm wrong and no c-factor exists.)

Now, suppose that someone advocates the many-worlds interpretation of quantum mechanics.  What else can you infer about them?

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I'm Not Saying People Are Stupid

39 Eliezer_Yudkowsky 09 October 2009 04:23PM

Razib summarized my entire cognitive biases talk at the Singularity Summit 2009 as saying:  "Most people are stupid."

Hey!  That's a bit unfair.  I never said during my talk that most people are stupid.  In fact, I was very careful not to say, at any point, that people are stupid, because that's explicitly not what I believe.

I don't think that people who believe in single-world quantum mechanics are stupid.  John von Neumann believed in a collapse postulate.

I don't think that philosophers who believe in the "possibility" of zombies are stupid.  David Chalmers believes in zombies.

I don't even think that theists are stupid.  Robert Aumann believes in Orthodox Judaism.

And in the closing sentence of my talk on cognitive biases and existential risk, I did not say that humanity was devoting more resources to football than existential risk prevention because we were stupid.

There's an old joke that runs as follows:

A motorist is driving past a mental hospital when he gets a flat tire.
He goes out to change the tire, and sees that one of the patients is watching him through the fence.
Nervous, trying to work quickly, he jacks up the car, takes off the wheel, puts the lugnuts into the hubcap -
And steps on the hubcap, sending the lugnuts clattering into a storm drain.
The mental patient is still watching him through the fence.
The motorist desperately looks into the storm drain, but the lugnuts are gone.
The patient is still watching.
The motorist paces back and forth, trying to think of what to do -
And the patient says,
"Take one lugnut off each of the other tires, and you'll have three lugnuts on each."
"That's brilliant!" says the motorist.  "What's someone like you doing in an asylum?"
"I'm here because I'm crazy," says the patient, "not because I'm stupid."