# Overlap coefficient

The overlap coefficient,[1] or Szymkiewicz–Simpson coefficient, 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 smaller of the size of the two sets:

${\displaystyle \operatorname {overlap} (X,Y)={\frac {|X\cap Y|}{\min(|X|,|Y|)}}}$

If set X is a subset of Y or the converse then the overlap coefficient is equal to 1.

## References

1. ^ Vijaymeena, M. K.; Kavitha, K. (March 2016). "A Survey on Similarity Measures in Text Mining" (PDF). Machine Learning and Applications: An International Journal. 3 (1): 19–28. doi:10.5121/mlaij.2016.3103.