diff --git a/src/edit_distances.jl b/src/edit_distances.jl
index 02a544a..6ce494c 100644
--- a/src/edit_distances.jl
+++ b/src/edit_distances.jl
@@ -21,7 +21,7 @@ hamming(s1::AbstractString, s2::AbstractString) = evaluate(Hamming(), s1, s2)
 ##
 ## Levenshtein and Damerau Levenshtein
 ## Source Levenshtein: http://blog.softwx.net/2014/12/optimizing-levenshtein-algorithm-in-c.html
-##  Source DamerauLevenshtein: http://blog.softwx.net/2015/01/optimizing-damerau-levenshtein_15.html
+## Source DamerauLevenshtein: http://blog.softwx.net/2015/01/optimizing-damerau-levenshtein_15.html
 ##
 ##############################################################################
 
@@ -162,7 +162,7 @@ end
 
 function evaluate(dist::JaroWinkler, s1::AbstractString, s2::AbstractString) 
     length(s1) > length(s2) && return evaluate(dist, s2, s1)
-    length(s2) == 0 && return 0.0
+    length(s2) == 0 && return 1.0
 
     maxdist = max(0, div(length(s2), 2) - 1)
     m = 0 # matching characters
@@ -186,7 +186,7 @@ function evaluate(dist::JaroWinkler, s1::AbstractString, s2::AbstractString)
             end
         end
     end
-    m == 0.0 && return 0.0
+    m == 0.0 && return 1.0
     score = (m / length(s1) + m / length(s2) + (m - t) / m) / 3.0
 
     # common prefix adjustment
@@ -205,7 +205,7 @@ function evaluate(dist::JaroWinkler, s1::AbstractString, s2::AbstractString)
             score += (1 - score) * (m - (l + 1)) / (length(s1) + length(s2) - (2 * (l - 1)))
         end
     end
-    return score
+    return 1 - score
 end
 
 function jaro_winkler(s1::AbstractString, s2::AbstractString; 
diff --git a/src/qgrams_distances.jl b/src/qgrams_distances.jl
index 8276995..728f5c6 100644
--- a/src/qgrams_distances.jl
+++ b/src/qgrams_distances.jl
@@ -35,9 +35,9 @@ Base.in{Tv, Ti}(x::Tv, bag::Bag{Tv, Ti}) = get(bag.dict, x, 0) > 0
 function Base.length(bag::Bag)
     v = values(bag.dict)
     if isempty(v)
-        0
+        return 0
     else
-        mapreduce(x -> max(x, 0), +, values(bag.dict))
+        return mapreduce(x -> max(x, 0), +, values(bag.dict))
     end
 end
 
@@ -101,8 +101,8 @@ function evaluate(dist::Cosine, s1::AbstractString, s2::AbstractString)
             count += bag1.dict[x] * bag2.dict[x]
         end
     end
-
-    return 1.0 - count / (sqrt(sumabs2(values(bag1.dict))) * sqrt(sumabs2(values(bag2.dict))))
+    denominator = sqrt(sumabs2(values(bag1.dict))) * sqrt(sumabs2(values(bag2.dict)))
+    denominator == 0 ? 1.0 : 1.0 - count / denominator
 end
 
 cosine(s1::AbstractString, s2::AbstractString; q = 2) = evaluate(Cosine(q), s1, s2)
diff --git a/test/distances.jl b/test/distances.jl
index 0647595..304de9e 100644
--- a/test/distances.jl
+++ b/test/distances.jl
@@ -2,13 +2,13 @@
 using StringDistances, Base.Test
 
 
-@test_approx_eq_eps jaro_winkler("MARTHA", "MARHTA", boosting_threshold = 0.0, long_threshold = 100) 0.9611 1e-4
-@test_approx_eq_eps jaro_winkler("DWAYNE", "DUANE", boosting_threshold = 0.0, long_threshold = 100) 0.84 1e-4
-@test_approx_eq_eps jaro_winkler("DIXON", "DICKSONX", boosting_threshold = 0.0, long_threshold = 100) 0.81333 1e-4
-@test_approx_eq_eps jaro_winkler("William", "Williams", boosting_threshold = 0.0, long_threshold = 100) 0.975 1e-4
-@test_approx_eq_eps jaro_winkler("", "foo", boosting_threshold = 0.0, long_threshold = 100) 0.0 1e-4
-@test_approx_eq_eps jaro_winkler("a", "a", boosting_threshold = 0.0, long_threshold = 100) 1.0 1e-4
-@test_approx_eq_eps jaro_winkler("abc", "xyz", boosting_threshold = 0.0, long_threshold = 100) 0.0 1e-4
+@test_approx_eq_eps jaro_winkler("MARTHA", "MARHTA", boosting_threshold = 0.0, long_threshold = 100) 1 - 0.9611 1e-4
+@test_approx_eq_eps jaro_winkler("DWAYNE", "DUANE", boosting_threshold = 0.0, long_threshold = 100) 1 - 0.84 1e-4
+@test_approx_eq_eps jaro_winkler("DIXON", "DICKSONX", boosting_threshold = 0.0, long_threshold = 100) 1 - 0.81333 1e-4
+@test_approx_eq_eps jaro_winkler("William", "Williams", boosting_threshold = 0.0, long_threshold = 100) 1 - 0.975 1e-4
+@test_approx_eq_eps jaro_winkler("", "foo", boosting_threshold = 0.0, long_threshold = 100) 1.0 1e-4
+@test_approx_eq_eps jaro_winkler("a", "a", boosting_threshold = 0.0, long_threshold = 100) 0.0 1e-4
+@test_approx_eq_eps jaro_winkler("abc", "xyz", boosting_threshold = 0.0, long_threshold = 100) 1.0 1e-4
 
 
 
@@ -50,6 +50,6 @@ using StringDistances, Base.Test
 @test_approx_eq_eps jaccard("leia", "leela", q = 2) 0.83333 1e-4
 
 
-@test_approx_eq_eps cosine("", "abc", q = 2) NaN 1e-4
+@test_approx_eq_eps cosine("", "abc", q = 2) 1 1e-4
 @test_approx_eq_eps cosine("abc", "ccc", q = 2) 1 1e-4
-@test_approx_eq_eps cosine("leia", "leela", q = 2) 0.7113249 1e-4
\ No newline at end of file
+@test_approx_eq_eps cosine("leia", "leela", q = 2) 0.7113249 1e-4