diff --git a/examples/naivebayes-doc-classifier.hs b/examples/naivebayes-doc-classifier.hs
index ca9ba65..82becbf 100644
--- a/examples/naivebayes-doc-classifier.hs
+++ b/examples/naivebayes-doc-classifier.hs
@@ -17,18 +17,16 @@ module Main
       let intClasses = [0..length classes - 1]
           documents = createDocuments classes dataset
           testDocuments = createDocuments classes test
+          devTestDocuments = take 20 testDocuments
           nb = initialize documents
 
           results = map (\(Document text c) -> (c, determine text nb intClasses documents)) testDocuments
+          -- results = map (\(Document text c) -> (c, determine text nb intClasses documents)) devTestDocuments
 
       let showResults (c, r) = putStrLn (classes !! c ++ " ~ " ++ classes !! r)
       mapM_ showResults results
 
-      let showAccuracy (c, r) =
-            print $ genericLength (filter (\(h, j) -> h == j && h == c) results) / genericLength results
-      mapM_ showAccuracy results
-
-      putStrLn $ "Recall: " ++ show (recall results) ++ "%"
-      putStrLn $ "Precision: " ++ show (precision results) ++ "%"
+      putStrLn $ "Recall: " ++ show (recall results)
+      putStrLn $ "Precision: " ++ show (precision results)
       putStrLn $ "F Measure: " ++ show (fmeasure (precision results) (recall results))
-      putStrLn $ "Accuracy: " ++ show (accuracy results) ++ "%"
+      putStrLn $ "Accuracy: " ++ show (accuracy results)
diff --git a/src/Sibe/NaiveBayes.hs b/src/Sibe/NaiveBayes.hs
index e2444c4..7a7cd05 100644
--- a/src/Sibe/NaiveBayes.hs
+++ b/src/Sibe/NaiveBayes.hs
@@ -70,16 +70,16 @@ module Sibe.NaiveBayes
         go s (x:xs) = if x `Set.member` s then go s xs
                                           else x : go (Set.insert x s) xs
 
-    accuracy :: [(Int, Int)] -> Int
+    accuracy :: [(Int, Int)] -> Double
     accuracy results =
       let correct = filter (uncurry (==)) results
-      in round $ genericLength correct / genericLength results * 100
+      in genericLength correct / genericLength results
 
     recall :: [(Int, Int)] -> Double
     recall results =
       let classes = ordNub (map fst results)
           s = sum (map rec classes) / genericLength classes
-      in s * 100
+      in s
       where
         rec a =
           let t = genericLength $ filter (\(c, r) -> c == r && c == a) results
@@ -90,12 +90,15 @@ module Sibe.NaiveBayes
     precision results =
       let classes = ordNub (map fst results)
           s = sum (map prec classes) / genericLength classes
-      in s * 100
+      in s
       where
         prec a =
           let t = genericLength $ filter (\(c, r) -> c == r && c == a) results
               y = genericLength $ filter (\(c, r) -> r == a) results
-          in t / y
+          in
+            if y == 0
+              then 0
+              else t / y
 
     fmeasure :: Double -> Double -> Double
     fmeasure r p = (2 * p * r) / (p + r)