diff --git a/src/Evaluation.hs b/src/Evaluation.hs
new file mode 100644
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--- /dev/null
+++ b/src/Evaluation.hs
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+module Evaluation ( varianceOfProducedCompounds
+                  , meanOfDistinctCompounds
+                  ) where
+
+import Control.Foldl as F
+import Numeric.LinearAlgebra as LA
+
+import Environment
+
+eps :: Amount
+eps = 0.01
+
+varianceOfProducedCompounds :: [LA.Vector Amount] -> Double
+varianceOfProducedCompounds comps = F.fold F.variance $ sumElements <$> comps
+
+-- | count compound as active if it is over eps.
+meanOfDistinctCompounds :: [LA.Vector Amount] -> Double
+meanOfDistinctCompounds comps = F.fold F.mean $ sumElements . LA.cmap (\x -> if abs x < eps then 0 else 1) <$> comps
+
+-- TODO: Mean enzyme-activity?