Mark Twain talked about “lies, damned lies, and statistics.” Lying with statistics isn’t always intentional; sometimes a writer doesn’t understand their meaning or applicability.

Recently I saw a news article on the COVID-19 infection rate in northern New Hampshire. It reported a higher positivity rate than in previous weeks. That doesn’t tell us anything about whether infections are increasing or decreasing, though. If the positivity rate goes up, it could mean one of several things:

1. More people are infected.
2. More of the people who are infected are getting tested.
3. Fewer people who aren’t infected are getting tested.

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