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Dare Obasanjo wrote:
>For this to work (a) every description of a person must use the same data model & (b) there needs to exist a mapping from your applications data model to that of the unknown schema available somewhere. This seems fairly optimistic to me and highly unlikely in the geenral case in practice.
a) This is *explicity* untrue -- read the OWL requirements doc.
see 3.3 Ontology interoperability
"Different ontologies may model the same concept in different ways..."
as well as requirements:
b) mapping from "data model" to "schema" is done via URIs as well as the
The sum of this is that different models/ontologies of a "Person" can
interoperate. This is one of the huge benefits of *not* having a fixed
schema with represented as a fixed set of relational columns in which to
represent a person. Different ontologies might define different
properties of a person (each ontology defines the properties a
particular application might be interested in). *Somewhere else* an
inferencing engine can declare two "people" to the the same -- that is,
for example, one person represented in a credit card transaction
(identified via a signature and CC number) as the _same as_ another
representation of the _same_ person, perhaps identified by a different
credit card transaction, or perhaps as identified by a tax return
(social security number)... use your imagination. I am not saying that
there aren't processing issues *possible*, only that one does not need
to use a fixed "schema".
>Semantic Web proponents tend to gloss over these points whenever describing the Semantic Web utopia.
If you read the WebOnt use cases and requirements document, that is
explicitly not the case -- so perhaps what you say is true for "Semantic
Web proponents" who haven't been involved with the actual development of
semantic web standards.