The Sorensen Coefficient

The Sorensen Coefficient calculator computes a quotient of similarity for two communities based on the number of species in each community and the number of species in common.

INSTRUCTIONS: Enter the following:

• (c) Number of species in common between both communities.
• (S₁) Number of species in community one.
• (S₂) Number of species in community two.

Sorensen Coefficient (DSC): The calculator returns the coefficient. 

The Math / Science

The Sorensen Coefficient is a similarity index indicator on the number of individuals of species common to two communities.  The common set notation is:

   `DSC =( 2|XnnY| )/ (|X| + |Y|)`

where:

• X is a set
• Y is a set

The formula for the Sorensen Coefficient is:

           `"DSC" = (2*c) / (S_1 + S_2)`

where:

• DSC = Sorensen Coefficient (aka Quotient of Similarity)
• c- the number of species common to both communities
• S₁ - the number of species in community 1
• S₂- the number of species in community 2

The Sorenson Coefficient is also known as the "Quotient of Similarity".

Community Statistics Calculators 

• Sorensen Coefficient
• Jaccard Index
• Jaccard Index (simple)
• Simple Matching Coefficient
• One Way Analysis of Variance (ANOVA)
• Simple Statistics Calculator
• Sort a list of numeric values
• Create a random subset of the a list of numeric values
• Frequency distribution of data.
• Chi-Square Calculator

REFERENCE

[1]Booth, Barbara D., Stephen D. Murphy, and Clarence J. Swanton. Invasive Plant Ecology in Natural and Agricultural Systems. Cambridge, MA: CABI, 2011. Print.