Re:Cory Doctorow: Our dangerous statistical ignorance
by graywh on Wednesday May 21, 2008 @05:04PM
(#196553)
Not necessarily. If you get the same results every time, repeated testing provides nothing.
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Re:Cory Doctorow: Our dangerous statistical ignorance
by DougBTX on Wednesday May 21, 2008 @06:44PM
(#196638)
It depends on what causes the false positives.
If the test is picking up something in the person being tested, then yes, you'll get the same result every time and repeated testing proves nothing. But you can still repeat using other tests.
If the test gives false positives purely at random, then repeated testing will help. Say the test is wrong 50% of the time, and you do the test five times. If you get the same results every time, then you can be 100-(50/100)^5*100 = 97% sure of the results.