Saturday, July 18, 2009
Bayes' theorem makes it into the BBC
This article about false positives seems quite well done.
The BBC article links to an animation on the Understanding uncertainty website. I'm not sure if the animation is a good teaching aid - it shows the test being applied with a great random rattling of the faces of the 100 humans. I think it would be better to reveal the truth early so the viewer can understand the generative process, instead of it looking like every individual is being utterly randomized. I also find it confusing that colour (Red/green) is used initially to encode test result, then it is later used to encode the underlying truth. I think two different dimensions should have been used.
I'd reveal the truth, show the generative process, then hide the underlying truth to emulate "what the tester sees"; then reveal the truth again.
ps... I find it a bit uneasy-making that the whole set-up involves "detecting terrorists". The implicit endorsement of "war on terror"; the endorsement of the campaign to "be suspicious of your neighbours, look for stuff in their bins, and get them arrested and interrogated".
Posted by David MacKay FRS at 3:29 AM 1 comment:
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