Bayes Theorem

[cockandbull]

Has anyone any good advice for learning about this?

Thanks

Harry

[fnord_too]

wikipedia page (http://en.wikipedia.org/wiki/Bayes_Theorem)

Glancing at this page, it looks more intimidating than it should. Google works, too. It's pretty straight forward and simple, just work though some problems once you understand the basics.

[disjunction]

Yeah, Wikipedia always makes things too complicated for some reason.

He should skip down to the part in the big letters above "which is the theorem conventiaonally known as Bayes theorem".

To the original poster, just keep staring at the equation until you understand it. P(A|B) means Probability A given B. Try substituting things familiar to you for A and B. P(Having a Disease | Testing Positive for the Disease) is a good one.

[jedi]

You'll get better advice posting to the Probability forum.

[patrickb20]

The problem people have with reasoning is "Base Rate Neglect." Bayes rule addresses this. The final equation in lay man terms is = "true positive" / ("true positive" + "false positive"). Trying a couple problems will make understanding much easier. Check slides 4-16 at this website for a class I took. Very easy to understand: http://psiexp.ss.uci.edu/research/teachingP140C/2005/3_8.ppt