Er, the whole point of statistical inference (and intelligence more generally) is that you can get the most knowledge from the least data. In other words, so you can figure stuff out before learning it “the hard way”. If doctors “eventually figure out” that most positives don’t actually mean cancer, that means poor performance (judged against professionals in general), not good performance!
“Eventually” was byrnema’s usage—I’d bet doctors are probably told outright the positive and negative predictive values of the tests by the test designers.
Er, the whole point of statistical inference (and intelligence more generally) is that you can get the most knowledge from the least data. In other words, so you can figure stuff out before learning it “the hard way”. If doctors “eventually figure out” that most positives don’t actually mean cancer, that means poor performance (judged against professionals in general), not good performance!
“Eventually” was byrnema’s usage—I’d bet doctors are probably told outright the positive and negative predictive values of the tests by the test designers.