Your experience is that it gave very few false negatives in 1997, but you have no idea what its rate of false positives was b/c you presumably only entered your

Your experience is that it gave very few false negatives in 1997, but you have no idea what its rate of false positives was b/c you presumably only entered your own ID. The required rate of false positives for an iphone has to be orders of magnitude lower than a Safeway employee sign-in which additionally required a 6 digit ID. Plus the false negative rate has to be at least as good.