W3C home > Mailing lists > Public > public-owl-wg@w3.org > February 2009

Re: ACTION-264: Discuss imports with Tim Redmond.

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Thu, 12 Feb 2009 14:44:15 -0500 (EST)
Message-Id: <20090212.144415.167523374.pfps@research.bell-labs.com>
To: alanruttenberg@gmail.com
Cc: public-owl-wg@w3.org

From: Alan Ruttenberg <alanruttenberg@gmail.com>
Subject: ACTION-264: Discuss imports with Tim Redmond.
Date: Thu, 12 Feb 2009 08:04:25 -0800

> 
> I had a talk with Tim on tuesday. He is concerned with the following
> situation - a zip file of ontologies is sent, perhaps a development
> version of a modular ontology. Someone wants Protege to open and edit
> this ontology. He needs to examine the folder and figure out how to
> resolve the various imports. For the purposes of this discussion we
> can assume that all ontologies in the closure are in the folder.
> 
> How can he do this? He points out that the language we use is
> 
> If O contains an ontology IRI OI but no version IRI, then the ontology
> document of O should be accessible from the IRI OI.
> 
> He points out that this is different from saying
> 
> ... should be accessed from ...
> 
> or
> 
> ... and is the one that would be accessed.

How so?

> This could be fixed, in his opinion, by amending the description of
> canonical parsing.
> 
> Current:
> 
> CP-2.1	 Retrieve the ontology document DI from I as specified
> in Section 3.2. 
> 
> Since 3.2 only specifies where one might retrieve the document from
> (where it is accessible), tightening this to:
> 
> CP-2.1 Retrieve the ontology document DI from from a location that I
> 3.2 says it is accessible from.

Huh?  How can I (an IRI) say where it is accessible from?  

> We also discussed that having a portable way of specifying the a
> redirection mapping might better deal with this rather common case.

Why would this be better than the current case?

> -----
> 
> Our discussion pointed to two more issues to note:
> 
> 1) The current behavior of Protege 4 is that when loading an ontology
> from a file system, it always looks in the same directory for
> ontologies that are imported? Should this be the default behavior? I
> would argue not. Tools may implement a redirection mechanism, and
> protege 4 supplies one in the form of an ontology library mechanism
> where a set of directories to search is specified. Therefore absent an
> explicit mention of the "." directory in the ontology libraries the
> ontology should be accessed from IRI specified in the imports or
> versionuri statement.
> 
> In any case it would be nice if our document could say enough that the
> appropriate behavior could be determined.

What appropriate behaviour?  Are you arguing for something like "don't
put all your ontologies in one directory"?  What difference does this make?

> 2) He notes a case in the aforementioned zip file use case that can
> not be resolved at all:
> 
> Two ontologies in the zip file ("headers" below)
> 
> ontology foo versionuri bar
> ontology foo versionuri bar1
> 
> The document that is loaded has the following:
> import foo
>
> There is no way to determine which of the two documents on disk is to
> be preferred over the other.

Why not?  There are lots of ways that one could make this determination,
such as via file names, via IRI-to-file-name redirections, etc.  

> I don't see any way of repairing this, however it does suggest that
> enumerating a couple of examples might be a useful addition to our
> documentation.

What kind of examples?  There are currently three examples in the
document, and one of these is even for off-line processing.  I do not
think that it is the job of the WG to provide examples for cases that
don't related to the Semantic Web.

peter
Received on Thursday, 12 February 2009 19:43:59 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Thursday, 12 February 2009 19:44:01 GMT