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DAML+OIL: Questions & Improvements.

From: King . Dany <DKing@drc.com>
Date: Thu, 25 Jan 2001 15:36:35 -0500
Message-ID: <80090D89EF34D311B69F00508B2C6E4327C1D3@orl01.drc.com>
To: "'www-rdf-logic@w3.org'" <www-rdf-logic@w3.org>
Cc: TeamXML <TeamXML@drc.com>, "Randolph . Wayne" <WRandolph@drc.com>
The following questions/comments are about the DAML+OIL ontology version 1.6

1) The "versionInfo" element has a very weak definition: it is only one
element with no sub-elements.  The use of this element thus far exemplifies
the need for a better definition, for example.:

<versionInfo>$Id: daml+oil.daml,v 1.6 2001/01/11 20:39:28 mdean Exp

This element has been overloaded with many types of information: file name,
version index, date, time, modifier/creator, and some extra data "Exp".
Apparently this string is used by RCS or CVS.  Although the use of RCS/CVS
is a good practice, the use of this string in an XML document is not.  This
data should be captured by DAML+OIL in XML fashion: meaningful tags should
be made for each type of data.  If this string must appear in the document
for RCS/CVS purposes, then is should be embedded in an XML comment tag: <!--
-->.  However, the versionInfo element should still be populated with the
corresponding information.

Recommend using DRC Versioning Initiative (DRC-VI), use the following


Note: our webpage for the DRC-VI isn't active yet, but will be soon. The
element set will contain the following 11 elements:
	Element: versionInfo  --> root element
	Element: location  --> URL of the document
	Element: replaces  --> URL of the previous version
	Element: replacedBy  --> URL of the next version
	Element: version --> the version identifier
	Element: email  --> email address of the document's creator
	Element: status  --> indicator of the current state of the document,
i.e., completed, inwork, published, etc...
	Element: dc:title  --> the name of the document
	Element: dc:creator  --> the name of the creating individual or
	Element: dc:contributior  --> the name of a contributing individual
or company
	Element: dc:date  --> the date of the last status change
Hint: the CVS/RCS metadata string can be embedded in the "versionInfo" root
element as an XML comment: <!-- -->.

2) Why isn't the "Ontology" element at the beginning of the DAML+OIL
2.a) Why are there 2 imports: one in the "rdf:Description" element and the
other in the "Ontology" element?
2.b) Shouldn't "rdf:Description" element at the beginning of the DAML+OIL
ontology be the "Ontology" element?
2.c) Also, the original purpose of the "rdf:Description" element in an
ontology was for Mike Dean's crawler. If a robust versionInfo element, such
as the one described by the DRC-VI, is used there will be no need for a
"rdf:Description" in an otology.  All of the necessary information is
captured by the DRC-VI element set.

3) Why are there both prefixed and un-prefixed "Property" elements?
3.a) Is there a difference between the two types of definitions?
3.a.i) If so, why? And what is the difference?
3.a.ii) Since the DAML+OIL "Property" element is defined using the
"sameClassAs" property to be equivalent to the "rdf:Property", then aren't
the prefixed and the un-prefixed uses of "Property" equivalent?
3.a.iii) Or was it just a typo?

4) Since DAML+OIL equivalencies have been defined for RDF and RDFS elements
and attributes, why are the prefixed versions used at all?
4.a) Even though the RDF / RDFS prefixed elements and attributes are
technically valid in DAML+OIL, shouldn't their use be depreciated?
4.b) And, shouldn't the use of the equivalent DAML+OIL elements be
appreciated or strongly recommended?

5) The "Thing" class is not implemented properly.   The "Thing" class is
supposed to be the base class in DAML+OIL, however, it is currently just
another class which has no direct connection to any other class.  Per the
current DAML+OIL specification, the "rdf:Class" is the base class in
DAML+OIL.  Please review the attached PowerPoint presentation regarding the
problem (each slide has important notes).  Also, there are two solutions
described therein.  The Alternative Solution B is the most concise and is


The following questions/comments are directed at the example
ontology/instance (mostly v1.4):

6) Can you extend the example ontology and instance about "Adam".  For
example, include "Eve", "Cain" and "Able", along with both family and
non-family oriented relationships.
6.a)  How would the slaying of Able by Cain be described? 

7) Can you give an example for the "UniqueProperty".  Specifically, contrast
it with the example already given for "UnambiguousProperty".

8) What does "FvH" mean?  It is used in the XML comments throughout the
example (v1.1).

9) "hasSpouse" is referred to but never defined.

Thank you,
Dan King
Dynamics Research Corporation
Orlando, Florida

Received on Thursday, 25 January 2001 15:39:59 UTC

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