Originally Posted by
Pesky Monkey
Then can't we just skip the first guy and go directly to the one that is competent? Makes more sense.
Regarding the topic of specificity and sensitivity of tests (how no test will give 100% of either quantity - false positives and false negatives are always nonzero), I'd have to reluctantly say that having two people checking the same ID would reduce the likelihood of mistakes considerably. It's not unusual in a medical setting to do a test twice or even more times to be as sure as possible that the correct conclusion is reached. There is always some cost/benefit tradeoff, but the extra wages of one person probably could be justified.
BUT, that hinges on the assumption that we need ID checking at all. I don't feel that knowing who is on a plane makes the plane negligibly safer for the cost of civil liberties and make-work program.