My new hobby, as Randall Munroe sometimes says, is asking biomedical researchers what "sensitivity" and "specificity" mean. The modal response is "Um, yes, I always have to look those up".
But recently, preparing a homework assignment about the evaluation of binary classifiers, I had a flash of insight. My new insight answers one of the questions I've always had about these terms: Why do biomedical researchers focus on the (apparently misleading) concepts that "sensitivity" and "specificity" denote? (My other question remains unanswered: Why did they pick those singularly un-mnemonic names? As far as I can see, they might as well have called them "delicacy" and "capacity", or "intensity" and "curiosity", or "Jupiter" and "Saturn".)
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