--- a/dataset.py	Tue May 13 15:27:45 2008 -0400
+++ b/dataset.py	Tue May 13 15:29:04 2008 -0400
@@ -1096,6 +1096,8 @@
   given function example-wise or minibatch-wise to all the fields of
   an input dataset.  The output of the function should be an iterable
   (e.g. a list or a LookupList) over the resulting values.
+  
+  The function take as input the fields of the dataset, not the examples.
 
   In minibatch mode, the function is expected to work on minibatches
   (takes a minibatch in input and returns a minibatch in output). More