[uf-discuss] using microschema

Tantek Ç elik tantek at cs.stanford.edu
Sat Nov 24 23:59:13 PST 2007

On 11/24/07 9:25 PM, "Tatsuya Noyori" <nojorin at gmail.com> wrote:

> I would like to suggest microschema to improve interoperability of
> microformats.

Hi Tatsuya,

There are two general areas of problems that your suggestion.

The first is, what is the real world interoperability problem that you are
trying to solve?  

Do you have test cases that have been demonstrated to fail in specific

Do you have analysis that demonstrates that such problems stem from a lack
of an explicit typed schema?

Lacking that, it is not logical to conclude that a schema (micro or
otherwise) would help improve interoperability.

The second problem is that in practice, explicit schemas do not represent
all (often not even most) of the semantics of a specific format.  For
example, the HTML4 DTDs contain a mere fraction of the constraints and
semantics expressed by the HTML4 specification. A validator that only checks
the rules expressed in the HTML DTD will fail to check numerous assertions
and requirements made in the specification itself.  This is the schema
incompleteness problem.  In short, having a set of rules from a framework
(such as those expressed by a schema like a DTD) is not only in practice
insufficient, but serves to give a false sense of completeness of

Thus with microformats we eschew trying to solve the general schema problem
(others are trying much harder for much longer on that problem - e.g. XML
Schema etc., and failing in practice - i.e. usage on the Web) for simple
dictionaries instead.

There has been some value demonstrated in some scenarios (e.g. reading
microformats into an RDF store, either directly or thru a GRDDL transform)
to at least disambiguate the use of vocabulary, and back the terms used with
URLs.  Thus we have XMDP (XHTML Meta Data Profiles) which is sufficient to
define terms and provide a URL for each.



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