Lifting XML Schemas to RDF/OWL
Anthony Petosa, a colleague of mine, would like to request
feedback on these questions.
While the XML Schema language has a formal syntax and grammar that is
consumable by a machine, it cannot express the meaning of domain terms
in a way that is machine-understandable. For example, an XML Schema
"complexType" element may include multiple nested elements. Yet, the
relations of these elements to their containing element are
A second challenge is to codify the context of domain terms, which is
not always possible in an XML Schema definition. For example, an XML
Schema definition may include a sequence compositor with a number of
optional elements. Yet, the language does not allow us to determine if
one, some, all, or none of these elements must occur in a given XML
message. Instead a domain subject matter expert must convey the context
required for this determination, and XML Schema definitions must be
There is benefit in translating XML Schema language constructs to
RDF/OWL-DL, above all the ability to utilize RDF/OWL to check for
semantic consistency in XML messages and to reason over these messages.
The references below discuss "lifting" XML Schemas to RDF/OWL-DL. They
approach lifting XML Schema to RDF/OWL-DL differently, but they seem to
define mappings from XML Schema to RDF/OWL-DL constructs the same way.
For example, both  &  map <xsd:element> to <owl:ObjectProperty> if
it is a complexType element or to <owl:DatatypeProperty> if it is a
1. Is there consensus in the Semantic Web community on how XML Schema
language constructs map to RDF/OWL-DL language constructs?
2. Is there consensus in mapping to/from XML instance data and
RDF/OWL-DL instance data (i.e., OWL individuals)?
3. Assuming consensus for either 1 or 2, what tools exist that implement
5. If the tools are still formative, do any effective XML<-->RDF
algorithms exist that can be implemented code?
James R. Schoening
U.S. Army Net-Centric Data Strategy Center of Excellence
Voice: DSN 992-6820 or (732) 532-6820