Otsuka-Ochiai coefficient

$$sim_{OO}(x,y) = \frac{|x \cap y|}{\sqrt{|x|\cdot|y|}}$$

It’s like Cosine similarity but sets-based.

Reading

• Jiang, Yu, Guoliang Li, Jianhua Feng and Wen-Syan Li. “String Similarity Joins: An Experimental Evaluation.” Proc. VLDB Endow. 7 (2014): 625-636.