diff --git a/NLP/Scores.hs b/NLP/Scores.hs
--- a/NLP/Scores.hs
+++ b/NLP/Scores.hs
@@ -6,6 +6,7 @@
     , accuracy
     , recipRank
     , avgPrecision
+    , jaccard
     )
 where
 import Data.List hiding (sum)
@@ -52,3 +53,11 @@
     . mapAccumL (\z (r,rel) -> (z+rel,(r,rel,z+rel))) 0
     $ [ (r,fromEnum $ x `Set.member` gold) | (x,r) <- zip xs [1..]]
 
+-- | Jaccard coefficient
+-- J(A,B) = |AB| / |A union B|
+jaccard :: (Fractional n, Ord a) => Set.Set a -> Set.Set a -> n
+jaccard a b = 
+  fromIntegral (Set.size (Set.intersection a b))
+  / 
+  fromIntegral (Set.size (Set.union a b))
+  
diff --git a/nlp-scores.cabal b/nlp-scores.cabal
--- a/nlp-scores.cabal
+++ b/nlp-scores.cabal
@@ -7,7 +7,7 @@
 -- The package version. See the Haskell package versioning policy
 -- (http://www.haskell.org/haskellwiki/Package_versioning_policy) for
 -- standards guiding when and how versions should be incremented.
-Version:             0.1.0
+Version:             0.2.0
 
 -- A short (one-line) description of the package.
 Synopsis:            Scoring functions commonly used for evaluation in NLP and IR