Thank you John for your very helpful reply. You wrote "I suggest that you make a distinction between being able to do what the model does and a description of what he or she does - the fully coded representation." It has been my impression that I was keeping this distinction fairly clear.  It's not obvious to me right now what in my original message caused you to conclude that I can refine/start making this distinction? I'm curious to know if all the "modelling" you do is through an explicit arrangement with your exemplar or if you also do as I did and simply mimic the exemplar and complete your modelling process without the exemplar ever knowing.  If it is a mix of both aproaches, what criteria do you apply in deciding which approach to take? Most of your modelling work that I am aware of that has been described publicly involves an explicit arrangement with the exemplar. Thanks, Loren