diff --git a/flowchart/Flowchart.py b/flowchart/Flowchart.py
index 6b1352d5..5d7dc093 100644
--- a/flowchart/Flowchart.py
+++ b/flowchart/Flowchart.py
@@ -113,8 +113,11 @@ class Flowchart(Node):
         self.inputNode.setOutput(**args)
         
     def outputChanged(self):
-        self.widget().outputChanged(self.outputNode.inputValues())
-        self.sigOutputChanged.emit(self)
+        ## called when output of internal node has changed
+        vals = self.outputNode.inputValues()
+        self.widget().outputChanged(vals)
+        self.setOutput(**vals)
+        #self.sigOutputChanged.emit(self)
         
     def output(self):
         return self.outputNode.inputValues()
@@ -261,7 +264,9 @@ class Flowchart(Node):
     def process(self, **args):
         """
         Process data through the flowchart, returning the output.
-        Keyword arguments must be the names of input terminals
+        
+        Keyword arguments must be the names of input terminals. 
+        The return value is a dict with one key per output terminal.
         
         """
         data = {}  ## Stores terminal:value pairs
diff --git a/flowchart/Node.py b/flowchart/Node.py
index e6e98d1a..cd73b42b 100644
--- a/flowchart/Node.py
+++ b/flowchart/Node.py
@@ -229,7 +229,11 @@ class Node(QtCore.QObject):
         return "<Node %s @%x>" % (self.name(), id(self))
         
     def ctrlWidget(self):
-        """Return this Node's control widget."""
+        """Return this Node's control widget. 
+        
+        By default, Nodes have no control widget. Subclasses may reimplement this 
+        method to provide a custom widget. This method is called by Flowcharts
+        when they are constructing their Node list."""
         return None
 
     def bypass(self, byp):