concerning lite, fast, large versions of OWL

Although I am strongly in favor of having "classes as instances" in some 
version of OWL, I am also very strongly in favor of as simple as possible 
a view of our language.

Although consensus regarding the layering was a major accomplishment, it 
leaves us now with three versions of OWL: fast and large based on the RDF 
syntax/semantics, and of course the orthogonal "lite" version of the 

Having three versions of the language opens us up to some pretty obvious 
criticisms, in my view.  I think this would be even worse if OWL Lite, 
which is supposed to be a simplified version of OWL, is not a subset of 
Fast OWL, since Fast OWL is a subset of Large OWL.

I was passionately ambivalent about OWL Lite in general, but I would 
strongly object to it as yet another subset of Large OWL.  Several people 
have expressed opinions that "classes as instances" should be in OWL Lite. 
 I'm not sure why - if it is allowed in Large OWL, then what difference 
does it make if it is in OWL Lite?


Dr. Christopher A. Welty, Knowledge Structures Group
IBM Watson Research Center, 19 Skyline Dr.
Hawthorne, NY  10532     USA 
Voice: +1 914.784.7055,  IBM T/L: 863.7055
Fax: +1 914.784.6078, Email:

Received on Wednesday, 16 October 2002 21:03:20 UTC