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RE: RDF or UML (Was RE: XML and Healthcare,RDF spec bug was: Re:Default

• From: johns@s... (John F. Schlesinger)
• To: "'Bullard, Claude L (Len)'" <clbullar@i...>,'Jonathan Borden' <jborden@m...>
• Date: Fri, 21 Jul 2000 10:10:29 -0400

Len asked:

"How does RDF stack up next to UML for modeling semantics?"

It seems to me that RDF is at least 2 meta levels higher than UML (the
modeling language). Here is what UML 1.3 says about meta levels (excuse the
formatting):

"Layer		Description					Example
meta-metamodel 	The infrastructure for a		MetaClass, MetaAttribute,
			metamodeling architecture.		MetaOperation
			Defines the language for
			specifying metamodels.
metamodel 		An instance of a meta-metamodel.	Class, Attribute, Operation,
			Defines the					Component
			language for specifying a
			model.
model 		An instance of a metamodel.		StockShare, askPrice,
			Defines a language to			sellLimitOrder,
			describe an information			StockQuoteServer
			domain.
user objects (user data) An instance of a model.	<Acme_SW_Share_98789>,
			Defines a specific			654.56, sell_limit_order,
			information domain.			<Stock_Quote_Svr_32123>"

So, I think that RDF is at the meta-metamodel layer. UML is at the model
layer (with a subset based on UML Class diagrams at the metamodel layer).

In other words, RDF is a language that is so generic you can model any
meta-model in it. By the time you get to the model layer, languages are
specific to the thing being modeled. So UML is specific to object models (it
knows about visibility for example, a concept that doesn't exist in data
models). IDEF1X, on the other hand, is specific to data models (it knows
about identifying relationships, a concept that doesn't exist in object
models). Other modeling languages exist for modeling integrated circuits
(VHDL) and so on.

Yours,
John F Schlesinger
SysCore Solutions
212 619 5200 x 219
917 886 5895 Mobile

-----Original Message-----
From: Bullard, Claude L (Len) [mailto:clbullar@i...]
Sent: Friday, July 21, 2000 9:25 AM
To: Jonathan Borden
Cc: xml-dev@l...
Subject: RDF or UML (Was RE: XML and Healthcare,RDF spec bug was: Re:
Def ault Namespaces - why don't they apply toattributes?)


How does RDF stack up next to UML for modeling semantics?

Len Bullard
Intergraph Public Safety
clbullar@i...
http://fly.hiwaay.net/~cbullard/lensongs.ram

Ekam sat.h, Vipraah bahudhaa vadanti.
Daamyata. Datta. Dayadhvam.h

-----Original Message-----
From: Jonathan Borden [mailto:jborden@m...]

1) RDF was designed for modelling the rich types of semantic relationships

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  • RDF or UML (Was RE: XML and Healthcare,RDF spec bug was: Re: Def ault Namespaces - why don't they apply toattributes?)
    • From: "Bullard, Claude L (Len)" <clbullar@i...>

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