A person who tests positive is counted only once, but negative tests can be counted repeatedly if the same person got more than one test.
In addition, just as the pandemic raced out of control this month, the state changed the formula. It now mixes two different types of tests, including one that produces more false negative results.
The upshot of both factors is that the rate of positive tests, as quoted by the state, could make the situation look significantly better than it is, experts say.
How much the rate would change, if calculated differently, is impossible to know because the state refuses to release key pieces of raw data.