W3C home > Mailing lists > Public > public-semweb-lifesci@w3.org > July 2006

RE: LSIDs and ontology segmentation

From: Chimezie Ogbuji <ogbujic@bio.ri.ccf.org>
Date: Thu, 13 Jul 2006 16:10:21 -0400 (EDT)
To: w3c semweb hcls <public-semweb-lifesci@w3.org>
Message-ID: <Pine.GSO.4.60.0607131550260.11712@joplin.bio.ri.ccf.org>

> If o2 owl:imports o1, o2 is tightly bound to o1.  If I want to develop
> another ontology say, o3, and want to use the concepts of o2, I must also
> have to import the o1 as well.

I would think an ontology author would only import a second ontology 
if the terms / concepts within *depended* on terms / concepts in the 
second ontology, in which case it would follow that a third ontology (or an 
instance graph) that wanted to use o2  be required to import o1. By 
depend, I mean for purposes of reasoning.

> First, such kind of chain dependency will eventually leads to a
> big-monolithic ontology.

Only if the linking mechanism is done arbitrarily and without forethought 
with regard to recursive dependencies.  If the fragments are 
grouped atomically and distributed with links where the dependencies
  are neccessary, the 'trail' from the original ontology to all the 
included ontologies (the resulting closure) would be exactly the 
neccessary content to do reasoning with the terms used.

This of course, places a quite a burden on the ontology author to 
partition and link the ontologies with care, but I think this shifts the 
burden in the right direction.
> Second, it hurts the sharing capability of o2.  What if I only want to
> import o2 but not necessarily agree to o1?

If the linking is only used where the dependency is *neccessary* then the 
import is (essentially) transparent and irrelevant to a third ontology 
(or instance graph) that wishes to use terms from o2.

>  I must either pay the price,
> i.e, to be forced into using o1. Or impossible because I might have some
> assertions in o3 that might incur inconsistency with o1 but not necessarily
> o2.

Once again, if o1 is imported from o2 because it relies on the terms in 
o2, there wouldn't be any inconsistencies, and if there are it is more 
likely due to improper fragmentation / linking by the author than 
a unintended / unexpected use of the ontology terms.

Chimezie Ogbuji
Lead Systems Analyst
Thoracic and Cardiovascular Surgery
Cleveland Clinic Foundation
9500 Euclid Avenue/ W26
Cleveland, Ohio 44195
Office: (216)444-8593
Received on Thursday, 13 July 2006 20:10:33 UTC

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