You can see this everywhere! For example, many colleges were proud about their very low COVID positivity rates, without remarking that negative people required

You can see this everywhere! For example, many colleges were proud about their very low COVID positivity rates, without remarking that negative people required twice-a-week testing (so a very high total # of tests) whereas positive cases went on a multi-month testing lockout (for a good reason as you can still shed virus without being infections). Positivity on campus is, of course, a useful signal but comparing positivity in populations with mandatory testing and ones without (e.g. city COVID testing sites used by people with symptoms or those who travel) is very much apples-and-oranges. Or, in patent cases the defendant will want to narrow the scope as much as possible, whereas the plaintiff will argue for a very broad reading.