Bayesian prior: Difference between revisions

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:—Mike Tyson
:—Mike Tyson
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{{dpn|beɪzˈiːən ˈpraɪə|n|}}A way to incorporate existing knowledge or beliefs about a parameter into statistical analysis. For example, if you believe that (a) all playwrights can be objectively ranked according to independent, observable criteria; (b) the quality of those playwrights in a given sample will be normally distributed; and you think the best way of assessing the quality of dramas is by statistical analysis, than
{{dpn|beɪzˈiːən ˈpraɪə|n|}}A way to incorporate existing knowledge or beliefs about a parameter into statistical analysis. For example, if you believe that  
(a) you have already made several category errors and should not be talking about are trying to estimate the likelihood that a specific Elizabethan playwright really was the best playwright in history and didn’t just somehow fluke it, then your knowledge that there were vastly fewer active playwrights in the Elizabethan period than have existed in all of dramatic history until now, you might conclude that the odds of that Elizabethan playwright really being the best are vanishingly low.  
:(a) all playwrights can be objectively ranked according to independent, observable criteria;  
:(b) the quality of those playwrights in a given sample will be normally distributed;  
and you think the best way of assessing the quality of dramas is by statistical analysis, then
:(i) you have already made several category errors, should not be talking about art, and if you are, no-one should be listening; but
:(ii) if, nonetheless, you are, and they are, and you are trying to estimate the statistical likelihood of a specific Elizabethan playwright being the best in history, then your knowledge that there were vastly fewer playwrights active in the Elizabethan period than have existed in all of history until now — which is a Bayesian prior distribution — might help you conclude that the odds of that Elizabethan playwright really being the best are vanishingly low.  


At the same time, everyone else will conclude that you have no idea about aesthetics, and a fairly shaky grasp even of Bayesian statistics.
At the same time, everyone else will conclude that you have no idea about aesthetics and a fairly shaky grasp even of Bayesian statistics.


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