W3C home > Mailing lists > Public > www-webont-wg@w3.org > June 2003

Re: Proposed response to Golbeck regarding imports issue

From: Guus Schreiber <schreiber@cs.vu.nl>
Date: Mon, 16 Jun 2003 17:08:29 +0200
Message-ID: <3EEDDD6D.2060903@cs.vu.nl>
To: Jeff Heflin <heflin@cse.lehigh.edu>
CC: Jim Hendler <hendler@cs.umd.edu>, "Smith, Michael K" <michael.smith@eds.com>, WebOnt <www-webont-wg@w3.org>

Jeff Heflin wrote:
> Mike's text works for me too. Once I get Guus's approval/edits on my
> proposed wording for Reference, I'll incorporate everything into a
> revised proposed response to Jen.
> I also have Dave Beckett's imports comment to deal with. It mentions the
> same changes to Reference that I am awaiting for Guus to look at.
> Assuming he is OK with these or has minor changes, can I send that
> response once I hear from him? (Jim, I know you've already approved that
> response, so this question is really more directed at Guus and Dan).


You proposed two changes to Reference:

Jeff Heflin wrote:

 > Finally, you mention the wording in the documents:
 > First you discuss the following passage from the reference document,
 > 7.3:
 > "Note that the importing a document is different than creating a
 > namespace reference. owl:imports do not set up a shorthand notation for
 > names as does a namespace reference. On the other hand, the namespace
 > reference does not imply that all (or even any) ontological terms from
 > that namespace are being imported. Therefore, it is common to have a
 > corresponding namespace declaration for any ontology that is
 > imported."
 > You are correct that there are a few problems here: First, we are
 > inventing the term "namespace reference" when we mean "namespace
 > declaration." Second, the point of this paragraph was to comment on why
 > namespace declarations and imports are both needed, not to comment on
 > how systems might follow links. In particular, we were trying to say
 > that they are very different animals. I suggest the following rewording:
 > "Note that although owl:imports and namespace declarations may appear
 > redundant, they actually serve very different purposes. Namespace
 > declarations simply set up a shorthand for referring to identifiers.
 > They do not implicitly include the meaning of documents located at the
 > URI (although some applications may choose to process these documents in
 > addition to the original document). On the other hand, owl:imports does
 > not provide any shorthand notation for referring to the identifiers from
 > the imported document. Therefore, it is common to have a corresponding
 > namespace declaration for any ontology that is imported."

Change is OK with me.

Jeff Hefline wrote:

 > Jim,
 > Sorry I don't have the practice writing responses that the rest of you
 > do. I'll get this right eventually :-). Anyway, I agree with your
 > suggestion to add some wording, and that Reference seems like the best
 > place to put it. Paraphrasing part of my proposed response, we could add
 > the following to the end of Section 7.3:
 > "Note that whether or not an OWL tool must load an imported ontology
 > depends on the purpose of the tool. If the tool is a complete reasoner
 > (including complete consistency checkers) then it must load all of the
 > imported ontologies. Other tools, such as simple editors and incomplete
 > reasoners, may choose to load only some or even none of the imported
 > ontologies."

Also OK.

> Jeff
> Jim Hendler wrote:
>>At 11:13 AM -0500 6/13/03, Smith, Michael K wrote:
>>>I have merged Jeff's suggestion with Ian's and propose that in the
>>>Guide, section 2.2, I replace the current text (see below) with the
>>>An owl:imports statement references another OWL ontology.  The URI
>>>that is the value of the rdf:resource attribute identifies the
>>>ontology to be imported. The current ontology is extended with the
>>>contents of the referenced ontology. Importing an ontology, O2, will
>>>also import all of the ontologies that O2 imports.
>>>Thus, if ontology A imports ontology B, the meaning of terms in A
>>>are exactly the same as they would be if all of the statements in B
>>>(including further imports statements) were included in A.
>>>It is often convenient to coordinate owl:imports with a namespace
>>>declaration, so that qualified names can be used when referring to the
>>>resources of the ontology. Notice the distinction between these two
>>>mechanisms. The namespace declarations provide a convenient means to
>>>reference names defined in other OWL ontologies, while owl:imports
>>>indicates an intention to include the assertions of the target
>>>Current text
>>>owl:imports provides an include-style mechanism. owl:imports takes a
>>>single argument, identified by the rdf:resource attribute.
>>>Importing another ontology brings the entire set of assertions
>>>provided by that ontology into the current ontology. In order to make
>>>best use of this imported ontology it would normally be coordinated
>>>with a namespace declaration. Notice the distinction between these two
>>>mechanisms. The namespace declarations provide a convenient means to
>>>reference names defined in other OWL ontologies. Conceptually,
>>>owl:imports is provided to indicate your intention to include the
>>>assertions of the target ontology. Importing another ontology, O2,
>>>will also import all of the ontologies that O2 imports.
>>That works for me.  Jeff, don't forget that you have to send a
>>response to Jen, and none has been approved yet
>>  -JH

Free University Amsterdam, Computer Science
De Boelelaan 1081a, 1081 HV Amsterdam, The Netherlands
Tel: +31 20 444 7739/7718
E-mail: schreiber@cs.vu.nl
Home page: http://www.cs.vu.nl/~guus/
Received on Monday, 16 June 2003 11:08:35 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 7 December 2009 10:58:01 GMT