Overlap coefficient

Template:Short description The overlap coefficient,Template:Refn or Szymkiewicz–Simpson coefficient,Template:Citation needed^[1]^[2]^[3] is a similarity measure that measures the overlap between two finite sets. It is related to the Jaccard index and is defined as the size of the intersection divided by the size of the smaller of two sets:

overlap (A, B) = \frac{| A \cap B |}{min (| A |, | B |)}

Note that $0 \leq overlap (A, B) \leq 1$ . If set A is a subset of B or the converse, then the overlap coefficient is equal to 1.

Notes

↑ Sager, W. K. H.; Lockemann, P. C. (1976). "Classification of Ranking Algorithms". International Forum on Information and Documentation. 1 (4): 12–25. Cite error: <ref> tag with name "SagerLockemann" defined in <references> is not used in prior text.
↑ McGill, M.; Koll, M.; Noreault, T. (October 1979). An Evaluation of Factors Affecting Document Ranking by Information Retrieval Systems, Syracuse, NY: School of Information Studies, Syracuse University. Cite error: <ref> tag with name "McGill1979" defined in <references> is not used in prior text.
↑ Simpson, G. G. (January 1943). "Mammals and the Nature of Continents". American Journal of Science. 241 (1): 1–31.
↑ Simpson, G. G. (July 1947). "Holarctic Mammalian Faunas and the Continental Relationships During the Cenozoic". Bulletin of the Geological Society of America. 58 (7): 613–688.
↑ Simpson, G. G. (1960). "Notes on the Measurement of Faunal Resemblance". American Journal of Science. 258-A: 300–311.