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<DIV><B>"Are the semantics encoded in the XML Schema or in the structure of the
XML instance documents that validate against that schema? Is it possible to
'understand' an instance document without reference to the
schema?"</B><BR><BR>Possible answers are:<BR></DIV>
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<LI><B>Yes:</B> you can understand an XML instance document in the absence
of a schema it validates against i.e. just from the structure of the
elements and the namespaces used.<BR>
<LI><B>No</B>: you require the XML Schema to understand the document.
</LI></OL></BLOCKQUOTE>
<P dir=ltr> </P>
<P dir=ltr><FONT face=Arial color=#0000ff size=2>Roger, If you postulate that
the instance document is valid against the schema, and the that the element and
attribute names are meaningful to the reader (a human, or software written by a
human who understands their meaning), then the only additional semantics the
schema could provide would be in the annotations/documentation, if any exist in
the schema. </FONT></P>
<P dir=ltr><FONT face=Arial color=#0000ff size=2>I'm not entirely sure what you
include in [data] "structure", but if you only mean concepts such as
tuples, trees, sets, lists, bags, etc., then I would disagree that
semantics are encoded substantially in data structure (of the XML instance doc
or any other record). It is true that without proper structure,
semantics cannot be encoded, but I think semantics are encoded predominantly in
class/element-attribute names and any referenced documentation (i.e., natural
language). If you replace meaningful names with surrogate keys (e.g.,
integers) and thereby obscure any meaning conveyed by the names, then the
instance document would lose a lot of its meaning.</FONT></P>
<P dir=ltr><FONT face=Arial color=#0000ff size=2>I'm not exactly sure how this
relates to the earlier discussion about XML schema, RDF, and more powerful
modeling methodologies like UML. but I hope it helps.</FONT></P>
<P dir=ltr><FONT face=Arial color=#0000ff size=2>Cheers,</FONT></P>
<P dir=ltr><FONT face=Arial color=#0000ff
size=2>-Stan </FONT></P>
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