diff --git a/action/action.py b/action/action.py
index 8473a1a2..cea9fa65 100644
--- a/action/action.py
+++ b/action/action.py
@@ -1,3 +1,4 @@
+
 class Action(object):
     """
         base class for Trainer and Tester
diff --git a/action/tester.py b/action/tester.py
index 591d75ce..0bce1c5d 100644
--- a/action/tester.py
+++ b/action/tester.py
@@ -14,6 +14,7 @@ class Tester(Action):
         self.test_args = test_args
         self.args_dict = {name: value for name, value in self.test_args.__dict__.iteritems()}
         self.mean_loss = None
+        self.output = None
 
     def test(self, network, data):
         # transform into network input and label
@@ -22,6 +23,7 @@ class Tester(Action):
         # split into batches by self.batch_size
         iterations, test_batch_generator = self.batchify(X, Y)
 
+        batch_output = list()
         loss_history = list()
         # turn on the testing mode of the network
         network.mode(test=True)
@@ -31,6 +33,7 @@ class Tester(Action):
 
             # forward pass from tests input to predicted output
             prediction = network.data_forward(batch_x)
+            batch_output.append(prediction)
 
             # get the loss
             loss = network.loss(batch_y, prediction)
@@ -39,7 +42,16 @@ class Tester(Action):
             self.log(self.make_log(step, loss))
 
         self.mean_loss = np.mean(np.array(loss_history))
+        self.output = self.make_output(batch_output)
 
     @property
     def loss(self):
         return self.mean_loss
+
+    @property
+    def result(self):
+        return self.output
+
+    def make_output(self, batch_output):
+        # construct full prediction with batch outputs
+        raise NotImplementedError
diff --git a/action/trainer.py b/action/trainer.py
index f4429a98..e00aff08 100644
--- a/action/trainer.py
+++ b/action/trainer.py
@@ -1,4 +1,5 @@
 from action.action import Action
+from action.tester import Tester
 
 
 class Trainer(Action):
@@ -6,9 +7,54 @@ class Trainer(Action):
         Trainer for common training logic of all models
     """
 
-    def __init__(self, arg):
+    def __init__(self, train_args):
+        """
+        :param train_args: namedtuple
+        """
         super(Trainer, self).__init__()
-        self.arg = arg
+        self.train_args = train_args
+        self.args_dict = {name: value for name, value in self.train_args.__dict__.iteritems()}
+        self.n_epochs = self.train_args.epochs
+        self.validate = True
+        self.save_when_better = True
 
-    def train(self, args):
+    def train(self, network, data, dev_data):
+        X, Y = network.prepare_input(data)
+
+        iterations, train_batch_generator = self.batchify(X, Y)
+        loss_history = list()
+        network.mode(test=False)
+
+        test_args = "..."
+        evaluator = Tester(test_args)
+        best_loss = 1e10
+
+        for epoch in range(self.n_epochs):
+
+            for step in range(iterations):
+                batch_x, batch_y = train_batch_generator.__next__()
+                prediction = network.data_forward(batch_x)
+                loss = network.loss(batch_y, prediction)
+                network.grad_backward()
+                loss_history.append(loss)
+                self.log(self.make_log(epoch, step, loss))
+
+            # evaluate over dev set
+            if self.validate:
+                evaluator.test(network, dev_data)
+                self.log(self.make_valid_log(epoch, evaluator.loss))
+                if evaluator.loss < best_loss:
+                    best_loss = evaluator.loss
+                    if self.save_when_better:
+                        self.save_model(network)
+
+        # finish training
+
+    def make_log(self, *args):
+        raise NotImplementedError
+
+    def make_valid_log(self, *args):
+        raise NotImplementedError
+
+    def save_model(self, model):
         raise NotImplementedError
diff --git a/model/base_model.py b/model/base_model.py
index 3298c3d6..f4fdf120 100644
--- a/model/base_model.py
+++ b/model/base_model.py
@@ -18,3 +18,30 @@ class BaseModel(object):
 
     def loss(self, pred, truth):
         raise NotImplementedError
+
+
+class Vocabulary(object):
+    """
+        A collection of lookup tables.
+    """
+
+    def __init__(self):
+        self.word_set = None
+        self.word2idx = None
+        self.emb_matrix = None
+
+    def lookup(self, word):
+        if word in self.word_set:
+            return self.emb_matrix[self.word2idx[word]]
+        return LookupError("The key " + word + " does not exist.")
+
+
+class Document(object):
+    """
+        contains a sequence of tokens
+        each token is a character with linguistic attributes
+    """
+
+    def __init__(self):
+        # wrap pandas.dataframe
+        self.dataframe = None