An indicator is said to valid if

Ans) b (It measures the thing.. ) Ref park 20th ed p 226The term validity refers to what extent the test accurately measures which it purports/ intended to measure.Validity expresses the ability of a test to separate or distinguish those who have the disease from those who do not have.Validity has two components - Sensitivity and specificitySensitivity and specificity together with "predictive accuracy" are inherent properties of a screening test.