Comments on: An Intuitive (and Short) Explanation of Bayes’ Theorem http://betterexplained.com/articles/an-intuitive-and-short-explanation-of-bayes-theorem/ Learning shouldn't hurt. Let's share the insights that made difficult ideas click. Fri, 6 Nov 2009 22:26:19 -0800 http://wordpress.org/?v=2.8.4 hourly 1 By: Emily Riley http://betterexplained.com/articles/an-intuitive-and-short-explanation-of-bayes-theorem/#comment-260751 Emily Riley Thu, 29 Oct 2009 09:58:12 +0000 http://betterexplained.com/articles/an-intuitive-and-short-explanation-of-bayes-theorem/#comment-260751 Thanks for writing this!! Even my stats prof was making this too difficult for everyone, but you have simplified it for me. I now have an understanding of the Bayes formula (enough to write my midterm this morning :D ). Thanks for writing this!! Even my stats prof was making this too difficult for everyone, but you have simplified it for me. I now have an understanding of the Bayes formula (enough to write my midterm this morning :D ).

]]> By: Dan Weisberg http://betterexplained.com/articles/an-intuitive-and-short-explanation-of-bayes-theorem/#comment-254339 Dan Weisberg Fri, 02 Oct 2009 17:40:07 +0000 http://betterexplained.com/articles/an-intuitive-and-short-explanation-of-bayes-theorem/#comment-254339 This is one of the best explanations I've found. Perhaps we can see if I really understand it by trying a real world problem I'm wrestling with. Here's the data: - The odds of a chest pain (CP) being caused by a heart attack is 40%. - The odds of a CP being caused by other factors (anxiety, depression, etc.) is 60%. - The odds of a heart attack occurring to a female above age 50 is 80%. - The odds of a heart attack occurring to a female under age 50 is 20%. I am presented with a 24 year old female who says she is having chest pain. What is the probability that her chest pain is caused by a heart attack? Is it 0.4 x 0.2 = 0.08? Also, 78% of patients having heart attacks present with diaphoresis (sweating), so 22% of patients having heart attacks don't sweat. This female is not sweating, so are the odds of her having a heart attack 0.22 x 0.08 = 0.0176? Thank you! This is one of the best explanations I’ve found. Perhaps we can see if I really understand it by trying a real world problem I’m wrestling with.

Here’s the data:
– The odds of a chest pain (CP) being caused by a heart attack is 40%.
– The odds of a CP being caused by other factors (anxiety, depression, etc.) is 60%.
– The odds of a heart attack occurring to a female above age 50 is 80%.
– The odds of a heart attack occurring to a female under age 50 is 20%.

I am presented with a 24 year old female who says she is having chest pain. What is the probability that her chest pain is caused by a heart attack? Is it 0.4 x 0.2 = 0.08?

Also, 78% of patients having heart attacks present with diaphoresis (sweating), so 22% of patients having heart attacks don’t sweat. This female is not sweating, so are the odds of her having a heart attack 0.22 x 0.08 = 0.0176?

Thank you!

]]> By: Better Explained « Xavier Seton’s Blog http://betterexplained.com/articles/an-intuitive-and-short-explanation-of-bayes-theorem/#comment-239475 Better Explained « Xavier Seton’s Blog Thu, 07 May 2009 07:37:33 +0000 http://betterexplained.com/articles/an-intuitive-and-short-explanation-of-bayes-theorem/#comment-239475 [...] Statistics: Combinations & permutations, Birthday Paradox, Bayes’ Theorem, [...] [...] Statistics: Combinations & permutations, Birthday Paradox, Bayes’ Theorem, [...]

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