Sorensen-Dice Coefficient

Sorensen-Dice coefficient, also called Dice coefficient or Czekanowski index, measures the similarity between two sets or samples based on presence and absence of attributes. Introduced independently by Thorvald Sorensen (1948) and Lee Dice (1945), this index ranges from 0 (completely dissimilar) to 1 (identical). It is particularly well-suited for binary presence-absence data and is the symmetric counterpart to the Bray-Curtis dissimilarity for abundance data.