Computing degree of similarity among a group of sets

Question

Suppose there are 4 sets:

s1={1,2,3,4};
s2={2,3,4};
s3={2,3,4,5};
s4={1,3,4,5};

Is there any standard metric to present the similarity degree of this group of 4 sets?

Thank you for the suggestion of Jaccard method. However, it seems pairwise. How can I compute the similarity degree of the whole group of sets?

Answer 1

Pairwise, you can compute the Jaccard distance of two sets. It's simply the distance between two sets, if they were vectors of booleans in a space where {1, 2, 3…} are all unit vectors.

Answer 2

Your question isn't very specific. But I suppose you mean something like the "edit distance" between them? I.e. how much you need to change s1 to get to s2?

Check out the Wikipedia article on Edit distance.