FW: A valuable lesson on the difference between XML Schemas and ontolog

["Costello, Roger L." <costello@mitre.org>]

An excellent message from Henry Thompson (see below).

-----Original Message-----
From: Henry S. Thompson [mailto:ht@inf.ed.ac.uk] 
Sent: Friday, November 04, 2011 3:55 PM
To: Eliot Kimber
Cc: Costello, Roger L.; xmlschema-dev@w3.org
Subject: Re: A valuable lesson on the difference between XML Schemas and ontologies

Eliot Kimber writes:

> XML schemas are nothing more than document syntax constraint specifications.
> There is no sense in which then can be anything more than a very weak
> reflection of some deeper ontology that governs the semantic objects for
> which the XML governed by the XSD schema is one possible serialization.
>
> That is, ontologies describe relationships among things, schemas define
> syntactic constraints on XML elements. The fact that the XSD mechanism has a
> weak facility for defining type hierarchies does not make it a language for
> describing taxonomies or ontologies.

Hear hear!  Confusing application domain analysis/data model design
with interchange/archival document language design is a fundamental
(albeit very common) mistake.  Don't do that.

ht
-- 
       Henry S. Thompson, School of Informatics, University of Edinburgh
      10 Crichton Street, Edinburgh EH8 9AB, SCOTLAND -- (44) 131 650-4440
                Fax: (44) 131 651-1426, e-mail: ht@inf.ed.ac.uk
                       URL: http://www.ltg.ed.ac.uk/~ht/
 [mail from me _always_ has a .sig like this -- mail without it is forged spam]