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Re: WEBONT "HOMEWORK" (DUE DATE approaching]

From: Michael Sintek <sintek@dfki.uni-kl.de>
Date: Thu, 29 Nov 2001 12:21:54 +0100
Message-ID: <3C061A52.7010907@dfki.uni-kl.de>
To: www-webont-wg@w3.org
CC: Michael Sintek <sintek@dfki.uni-kl.de>
The following are some passages from [1] which describes
the use of ontologies in the FRODO [2] project (and for
Knowledge Management in general).


In the FRODO project, we design a scalable, agent-based middleware for
distributed Organizational Memories (OM).

In knowledge management (KM), it is widely accepted that
ontologies as explicit specifications of conceptualizations
[Gruber91] provide a useful means to facilitate access
and reuse of knowledge. Typical utilization scenarios
comprise discussion groups, search engines,
information filtering, access to non-textual information objects,
and expert-user communication. In the context
of Organizational Memory (OM), ontologies provide a vocabulary for
specifying information resources as well as information needs
in order to evolve from a keyword-based towards a
concept-based information management, indexing, and
retrieval approach. They also form the basis for
knowledge-enhanced or knowledge-assisted search and retrieval.

In these applications, ontologies serve as formally represented
"specifications of discourse in the form of a shared vocabulary".
Such a shared understanding is particularly
important because KM typically deals with multi-actor scenarios.
The vision of knowledge management assumes the comprehensive use of an
enterprise's knowledge, whoever acquired it, whereever it is stored
and however it is formulated in particular. Technical support for
such a vision is often based on *centralized approaches*
which seem well-suited to guarantee that the *complete*
information available is considered. For
instance, in OM reference architecture (see attached figure) derived
from the KnowMore framework, the problem of several
heterogeneous information sources is tackled by the introduction
of a uniform *knowledge description level*: The various
information items are annotated by knowledge descriptions which
are based on an agreed upon vocabulary, namely the information,
enterprise, and domain ontologies. Hence, a centralized view upon
a distributed information landscape is built.

In the FRODO project we aim at extending
the centralized (KnowMore) framework towards a *distributed OM*
scenario, resulting in a need for *domain ontology services*.
This requires facilities for both adding domain
ontologies to an OM and accessing ontology services from other
OMs.

Therefore we propose two types of ontology services: Domain
Ontology Agents (DOA) and Distributed Domain Ontology Agents
(D2OA). Domain Ontology Agents are responsible for ontologies
*within one OM*, Distributed Domain Ontology Agents are
located *between several OMs* and facilitate cross-OM
communication.

So, the task of D2OAs is quite similar to "standard
information integration ontologies" (e.g. mapping services), but
much easier as the sources are already formal ontologies, not just
"any information provider".

Typical questions to DOAs are "What are the subconcepts of
concept A?" whereas D2OAs answer questions like "Which OM
contains concepts like A and B?" or "What does A mean in
OM_y?".

This structure better embraces the inherently distributed nature
of (ontological) knowledge. Not *all conceptualizations* are
shared between *all actors* of the system, but *ontology
societies* are formed with respect to relevant domains. Additional
infrastructure enables communication between these ontology
societies.

Michael

[1] http://citeseer.nj.nec.com/450299.html
[2] http://www.dfki.uni-kl.de/frodo/



knowmore.gif
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Received on Thursday, 29 November 2001 06:09:03 GMT

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