Top-down or bottom-up?

Paul Prescod paul at
Fri Jun 18 19:00:00 BST 1999

David Megginson wrote:
> I am quite comfortable helping to design a data model for XML, because
> XML *as a language* is a closed system; I am not (yet) comfortable
> helping to design a data model for the Web in general.  Perhaps we
> have been misunderstanding each-other.

Going back to square one: my assertion is that (useful!) languages are
encodings for concepts. XML is a language (primarily) for describing
elements and attributes.

We can only figure out (cumulatively) if the language is a good encoding
for the concept if we have communicated and agreed upon the concept first.
So if we thought through elements and attributes first, for example, we
would probably not have designed SG/XML with its limited attribute

But people prefer things that are concrete so they rush to the language
first. In OO terms they implement their objects before they have figured
out their object model. Thus we have URLs and URIs but no formal
definition of what they heck they are addressing.

Do I think that there should be a data model for the whole web? If there
were a formal definition for "the Web" then I could then profer an opinion
as to whether a data model for it is possible. 

I *do* think that we could develop a formal, extensible data model for
addressing (URLs) on the Internet. Many other interesting data models and
languages would build on that (RDF, XLink, schemas, etc.). The higher
level models would grow organically.

 Paul Prescod  - ISOGEN Consulting Engineer speaking for only himself

[Woody Allen on Hollywood in "Annie Hall"]
Annie: "It's so clean down here."
Woody: "That's because they don't throw their garbage away. They make 
        it into television shows."

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