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Re: Ontology "views"/"perspetcives"

From: Leo Obrst <lobrst@mitre.org>
Date: Fri, 14 Dec 2001 19:19:04 -0500
Message-ID: <3C1A96F8.BD20E623@mitre.org>
To: Jim Starz <jstarz@isx.com>
CC: www-rdf-logic@w3.org
Jim,

We identified this as a general problem with using ontologies: users
need this. Last year, we found out the hard way, building ontologies for
b2b e-commerce. One of the issues is trying to make the distinction
between "representation" and "presentation", i.e., you may have an
application which wants to display things in a particular way. At the
same time, however, you want your "categories" to be grounded in sound
representation, say in a reference ontology, in order to perform
automated
reasoning, for example, to assist search, etc. Plus, there is the usual
problem that if you allow arbitrary user creation of representation,
you'll get inconsistent and unsound junk. So the answer is in terms of
semantic mappings: between the taxonomy or classification system used by
the application and the reference ontology.  One solution of course is
to model the application "view" or, as we preferred, "context" (since
"view" has connotations in the database world and this is a toucher
semantic issue) in the ontology. A similar situation holds of course
between ontologies: what if you want to map between them?  We had a
paper in FOIS-01 [1] describing our experience and offering some
alternatives for mapping. We discuss ontology-ontology, application
taxonomy-ontology, and taxonomic standard-ontology, among others. 
It was our toughest technical issue.

Really there are two problems here, but very related: 1) semantic
mapping (between ontologies, e.g.), and 2) an
application/user/task/device "view" or "context" of a given ontology,
which largely really devolves to a mapping issue.

By the way, the new W3G Web Ontology Working Group is investigating use
cases for the language and one of which is "content interoperability" in
which I am involved (chair). So, please, if you have use cases
concerning
content interoperability for a web ontology language, send particulars
to me as soon as possible -- the more concrete and detailed the better. 

Here is an initial working description of "content interoperability", by
no means complete.

General Description:

Content Interoperability includes notions such as Semantic
Interoperability and interoperability issues dealing with the
distribution and mapping of content to devices. Semantic
Interoperability is roughly the capability to send and receive content
supported by ontologies across applications with retention of semantics,
the ability to map between different ontologies in a semantics
preserving manner. Other aspects: semantic equivalence, determining the
consistencies between two ontologies, ontology integration and merging. 

Included under this use case are:
- semantic mapping from database schemas to ontologies
- semantic mapping from taxonomies and classification systems to
ontologies
- semantic mapping from ontologies to ontologies
- mapping from ontology classes to ontology instances
- ontology partitioning and decomposition as the flip of ontology
integration and ontology merging
- ontology language extensions to support mapping ontologies
- electronic commerce standards and catalog mappings using ontologies
- dynamic composition of web services supported by independent
ontologies
- construction of an ontology "view" or presentation based on the needs
of a user, application, specific task using an ontology or ontologies,
and a device
- translating between ontologies
- merging ontologies

 Content Interoperability Subtasks:
- conceptual search to support ontology mapping
- versioning issues: once mappings are created, are they saved, are they
updated, what about when the 
ontologies themselves change over time
- support in the ontology language for user, task, application view and
context descriptions, constructions
- ability to annotate ontologies with meta-knowledge (and possible
reification)

[1] INTERNATIONAL CONFERENCE ON FORMAL ONTOLOGY IN INFORMATION SYSTEMS,
FOIS-2001, October 17-19, 2001, Ogunquit, Maine. ACM.
http://www.fois.org/fois-2001/index.html. Currently, only print is
available, but shortly will be in the ACM digital library.

Thanks,
Leo

> Jim Starz wrote:
> 
> Does anyone know of any work that has been done for ontology "views"
> or "perspectives" on the user level?  I am not referring to
> versioning, though the solution could probably leverage that work.
> 
> Here is the problem.  You have a (logical) ontology and many users
> that would like to customize the ontology for their use (have their
> own labels, ignore some properties, prefer certain properties).  The
> ultimate goal would be to allow the user to have a subset of the
> original ontology with some preferences (If I query for something that
> has a "name" property, I prefer to see the "common name", if none
> exists the "formal name").  All you really need is a mapping between
> the original ontology and these "views" and I was wondering if anyone
> had thought up a "common" language for that.  I don't think
> the solution is contained in RDFS/DAML, but maybe the webont group is
> addressing this.
> 
> thanks,
> Jim Starz
> ISX Corporation
> 

-- 
_____________________________________________
Dr. Leo Obrst		The MITRE Corporation
mailto:lobrst@mitre.org Intelligent Information Management/Exploitation
Voice: 703-883-6770	7515 Colshire Drive, M/S W640
Fax: 703-883-1379       McLean, VA 22102-7508, USA
Received on Friday, 14 December 2001 19:19:34 GMT

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