I don't understand what "base rates" means in this context. If you have a test result, that you think is showing something with a certain probability, which is

I don't understand what "base rates" means in this context. If you have a test result, that you think is showing something with a certain probability, which is higher then the current necessary confidence level required to trigger further probing, and it turns out afterwards it was a false positive, my naive way to go about this would be to raise the minimum confidence level afterwards (and vice versa if it's a true positive) Does this fail in horrible ways that I am missing right now?