Recall TP/+ FN (TP) is high, hope as much as possible is to is (TP), do not worry about negative patients to is (FP), are cases to negative cases of (FN) in order to ensure that all is be judgment is positive, criterion will tend to think the sample is positive example, at the same time will lead to more negative to positive,

Precision TP/+ FP (TP) is high, hope to patients as much as possible in the sample is just, don't worry about are cases to negative cases (FN), worry about negative patients to is (FP), to ensure that judgment was right in the case of samples are positive example, screening is standard will be more severe, will tend to think the sample is the judgment standard is negative example, at the same time will lead to more positive to negative,