Alan_Crowe comments on A Priori - Less Wrong

32 Post author: Eliezer_Yudkowsky 08 October 2007 09:02PM

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Comment author: Alan_Crowe 09 October 2007 05:49:11PM 0 points [-]

Occam's Razor has two aspects. One is model fitting. If the model with more free parameters fits better that could merely be because it has more free parameters. It would take a thorough Bayesian analysis to work out if it was really better. A model that fits just as well but with fewer parameters is obviously better.

Occam's Razor goes blunt when you already know that the situation is complicated and messy. In neurology, in sociology, in economics, you can observe the underlying mechanisms. It is obvious enough that there are not going to be simple laws. If two models fit equally well, you just don't know, even if one is simpler than the other.

The "quant" trying to make money on the financial markets can take a modelling approach and may find the Razor sharp, but the scientist, trying to get to the bottom of things, has little reason to go for an explanation simpler than the known complexity of the underlying mechanisms.