Re:Registered clinical trials make positive findings vanish
by rcthompson on Tuesday August 18, 2015 @07:27PM
(#10082855)
"Probability of getting a positive result by chance" and "probability of getting a positive result when there is no effect" are the same thing. This is what the p-value measures. (The full phrase is generally a combination of the two: "probability of getting a positive result by chance when there is no effect"; but that's so long that people shorten it.)
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Re:Registered clinical trials make positive findings vanish
by Alex3917 on Tuesday August 18, 2015 @07:31PM
(#10082870)
There are lots of reasons you could get a false positive result that have nothing to do with chance: e.g. non-representative sample, miscalibrated equipment, biased methodology, researcher fraud, flawed statistical analysis, etc.
C.f. http://blog.minitab.com/blog/adventures-in-statistics/how-to...
Re:Registered clinical trials make positive findings vanish
by rcthompson on Tuesday August 18, 2015 @07:41PM
(#10082908)
Indeed, but the comment that you quoted was referring to the case where the methodology and p-values are sound, and the only issue is testing multiple hypotheses without correction.