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ACTION-264: Discuss imports with Tim Redmond.

From: Alan Ruttenberg <alanruttenberg@gmail.com>
Date: Thu, 12 Feb 2009 08:04:25 -0800
Message-ID: <29af5e2d0902120804m253a1e18w9b2205bf47a5b5de@mail.gmail.com>
To: W3C OWL Working Group <public-owl-wg@w3.org>
Cc: Timothy Redmond <tredmond@stanford.edu>

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 ...


... and is the one that would be accessed.

This could be fixed, in his opinion, by amending the description of
canonical parsing.


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.

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

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.

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
Received on Thursday, 12 February 2009 16:05:04 UTC

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