Defining DataObject Types

Hi,

we have a question about defining of dataobject types in a component.

In every component you have written this:

   typedef typename Base::SetPointType SetPointType;
   typedef typename Base::InputType InputType;
   typedef typename Base::ModelType ModelType;
   typedef typename Base::OutputType OutputType;

Here seems that we don't know the types of DataObjects, but we have to know
them if we want to use its attributes/methods during the calculate(). It
isn't clear for us why you have 
done this choice. We think that you want to be sure that the DataObject
which is shared by 
two components is of the same type for both componets (which is the type
of the DataObject held by the Kernel).

Do we think right?

Andrea & Stefano