Something is not clear to me. How do you know that a false positive is, in fact, a false positive?<p>I presume there are some other pieces of information that provide the reference value.<p>So when someone gets a positive test, why not put them through the next test to see if they keep coming up positive?<p>What&#x27;s the argument for not testing in the first place? It will panic people? If that&#x27;s the case, why not make it random whether you&#x27;re called to an extra test?