Morendil comments on Priors and Surprise - Less Wrong

10 Post author: MichaelVassar 03 March 2010 08:27AM

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Comment author: Morendil 03 March 2010 08:58:40AM 10 points [-]

wondering whether Godzilla was a biological creature at all as opposed to, for instance, a giant robot left behind by an advanced and forgotten civilization

That's one of my main take-aways from PT:TLOS so far. (This post has reminded me of one of the exercises in the book.) The idea in Chap. 5 that given extremely unlikely priors for a hypothesis, strong evidence appearing to favor that hypothesis will not so much confirm it as call for the the resurrection of another, highly unlikely, but still more plausible than the original.

"You are being deceived" is advanced as a useful hypothesis to consider resurrecting in general. Perhaps conspiracy theorists are not as stupid as they sometimes appear; if you think the straightforward hypothesis unlikely enough, mass deception can be a more appealing hypothesis, with readily available mechanisms of explanation. (For instance a movie like The Truman Show couldn't work if we didn't assign a small degree of plausibility even to mass deception, given sufficient financial incentive.)

Comment author: GreenRoot 04 March 2010 05:45:33PM 6 points [-]
Comment author: Hook 03 March 2010 03:01:04PM 5 points [-]

Jaynes even uses the example of meteorites (aka thunderstones) to show that this line of reasoning, while valid by the laws of probability, can lead educated people to believe things that are not true.

The natural philosophers who knew something about gravity had a much higher prior probability for the unreliability of farmers' reports of natural phenomena than they did for rocks falling from the sky, so every report served to reinforce the hypothesis that farmers don't know what they are talking about. It took reports from people who were considered reliable in order for the meteorite hypothesis to be accepted.

How reliable a reporter would you need to call science in general into question?