• noun the ratio of non-relevant entries not retrieved to the total number of non-relevant entries contained in a file, database or library


  • The property that a policy measure applies to one or a group of enterprises or industries, as opposed to all industries.

Health Economics

  • (written as Specificity)
    The proportion of individuals without a condition that is correctly identified as such by a test. It is calculated thus: Specificity = TN/ (TN+FP), where TN is the number of true negatives and FP is the number of false positives. The terms 'positive' and 'negative' are used to refer to the presence or absence of the condition of interest. In the figure, specificity = d/ (b + d). A test that has low specificity will identify too many people as having the condition - the test is not specific enough.


  • noun the rate of negative responses in a test from persons free from a disease. A high specificity means a low rate of false positives.