The Math Behind False Positives and False Negatives

You probably know at this point in the pandemic that if you test positive on a rapid test (and you’ve used the test correctly–you’ve got to swab pretty hard!) that the odds are overwhelming that you have COVID and are infectious. You have, no doubt, been warned that a negative result on a rapid test should be taken with a grain of salt, especially if you’ve been exposed to the virus or you have symptoms. And you might have heard two terms about tests thrown around: sensitivity and specificity, particularly...