diff --git a/src/Data/Validity/Map.hs b/src/Data/Validity/Map.hs
--- a/src/Data/Validity/Map.hs
+++ b/src/Data/Validity/Map.hs
@@ -9,6 +9,10 @@
 
 -- | A 'Map' of things is valid if all the keys and values are valid and the 'Map' itself
 -- is valid.
-instance (Ord k, Validity k, Validity v) =>
-         Validity (Map k v) where
+instance (Ord k, Validity k, Validity v) => Validity (Map k v) where
     isValid m = M.valid m && all isValid (M.toList m)
+    validate m =
+        mconcat
+            [ M.valid m <?@> "The Map structure is valid."
+            , M.toList m <?!> "Map elements"
+            ]
diff --git a/src/Data/Validity/Sequence.hs b/src/Data/Validity/Sequence.hs
--- a/src/Data/Validity/Sequence.hs
+++ b/src/Data/Validity/Sequence.hs
@@ -8,6 +8,6 @@
 import Data.Sequence (Seq)
 
 -- | A 'Seq'uence of things is valid if all the elements are valid.
-instance Validity v =>
-         Validity (Seq v) where
+instance Validity v => Validity (Seq v) where
     isValid = all isValid . toList
+    validate s = toList s <?!> "Seq elements"
diff --git a/src/Data/Validity/Set.hs b/src/Data/Validity/Set.hs
--- a/src/Data/Validity/Set.hs
+++ b/src/Data/Validity/Set.hs
@@ -9,6 +9,10 @@
 
 -- | A 'Set' of things is valid if all the elements are valid and the 'Set' itself
 -- is valid.
-instance (Ord v, Validity v) =>
-         Validity (Set v) where
+instance (Ord v, Validity v) => Validity (Set v) where
     isValid s = S.valid s && all isValid (S.toList s)
+    validate s =
+        mconcat
+            [ S.valid s <?@> "The set structure is valid."
+            , all isValid (S.toList s) <?!> "Set elements"
+            ]
diff --git a/src/Data/Validity/Tree.hs b/src/Data/Validity/Tree.hs
--- a/src/Data/Validity/Tree.hs
+++ b/src/Data/Validity/Tree.hs
@@ -7,6 +7,6 @@
 import Data.Tree
 
 -- | A 'Tree' of things is valid if all the things in the 'Tree' are valid.
-instance Validity a =>
-         Validity (Tree a) where
+instance Validity a => Validity (Tree a) where
     isValid (Node rl sf) = isValid rl && isValid sf
+    validate (Node rl sf) = mconcat [rl <?!> "rootLabel", sf <?!> "subForest"]
diff --git a/validity-containers.cabal b/validity-containers.cabal
--- a/validity-containers.cabal
+++ b/validity-containers.cabal
@@ -1,5 +1,5 @@
 name: validity-containers
-version: 0.1.0.3
+version: 0.2.0.0
 cabal-version: >=1.10
 build-type: Simple
 license: MIT
@@ -25,8 +25,8 @@
         Data.Validity.Sequence
         Data.Validity.Set
     build-depends:
-        base >= 4.7 && <5,
-        validity >=0.3 && <0.4,
+        base >=4.7 && <5,
+        validity >=0.4 && <0.5,
         containers -any
     default-language: Haskell2010
     hs-source-dirs: src