J Am Med Inform Assoc 12:296-298 doi:10.1197/jamia.M1733
  • The Practice of Informatics
  • Technical Brief

Agreement, the F-Measure, and Reliability in Information Retrieval

  1. George Hripcsak,
  2. Adam S Rothschild
  1. Affiliation of the authors: Department of Biomedical Informatics, Columbia University, New York, NY
  1. Correspondence and reprints: George Hripcsak, MD, MS, Department of Medical Informatics, Columbia University, 622 West 168th Street, VC5, New York, NY 10032; e-mail: <hripcsak{at}>
  • Received 3 November 2004
  • Accepted 4 January 2005


Information retrieval studies that involve searching the Internet or marking phrases usually lack a well-defined number of negative cases. This prevents the use of traditional interrater reliability metrics like the κ statistic to assess the quality of expert-generated gold standards. Such studies often quantify system performance as precision, recall, and F-measure, or as agreement. It can be shown that the average F-measure among pairs of experts is numerically identical to the average positive specific agreement among experts and that κ approaches these measures as the number of negative cases grows large. Positive specific agreement—or the equivalent F-measure—may be an appropriate way to quantify interrater reliability and therefore to assess the reliability of a gold standard in these studies.


  • This work was funded by National Library of Medicine grants R01 LM06910 “Discovering and Applying Knowledge in Clinical Databases” and N01 LM07079 training grant.

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