Thanks Grahame, The UML specs definition of specialization matches what I thought it had meant.
I guess what I would like to understand is whether such a definition is true or not for archetypes? Is specialization in archetypes meant to support the definition you provided and the archetype editor is missing some functionality to ensure that only correctly specialized archetypes can be built? - or - Is it that archetypes and the editor supports some new semantics around specialization that I don't quite understand yet? I am sure Sam or Tom could shed some light on this ... Cheers, Andrew -----Original Message----- From: [email protected] [mailto:owner-openehr-technical at openehr.org] On Behalf Of Grahame Grieve Sent: Thursday, 26 May 2005 10:57 AM To: openehr-technical at openehr.org Subject: Re: The semantics of archetype Specialization Hi Andrew > Does anyone know what it actually means to specialize an archetype? And what > the rules are? The UML specification offers this definition for generalization: A taxonomic relationship between a more general element and a more specific element. The more specific element is fully consistent with the more general element and contains additional information. An instance of the more specific element may be used where the more general element is allowed I think that this is a fairly watertight definition and quite relevent to your question. > I looked at the archetype editor and created a specialized archetype of > another. The editor seemed to just copy the parent archetype and then > allowed the user to change anything about the archetype. > > For example, I can now make a mandatory field optional, or I can extend a > parent archetype with new mandatory fields that don't exist as optional > fields in the parent archetype By the UML definitions, these become "ill-formed" model. Of course, it's one thing to to state the definition, quite another to know how to compute whether a model is ill-formed. Grahame - If you have any questions about using this list, please send a message to d.lloyd at openehr.org
