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Proposed response to Hugh WInkler - allDisjoint

From: Jeremy Carroll <jjc@hpl.hp.com>
Date: Fri, 19 Sep 2003 14:20:46 +0300
To: www-webont-wg@w3.org
Message-Id: <200309191420.46851.jjc@hpl.hp.com>

Hugh was not aware of the solution in test I5.21 002, perhaps this should be a 
FAQ.

http://lists.w3.org/Archives/Public/public-webont-comments/2003Aug/0025

[[
Dear Hugh Winkler,

the WebOnt Working Group has considered this problem in detail.
We were aware that a few OWL users will have large numbers of disjoint 
classes, when we last formally considered this (during last call).

As part of the resolution in last call we added the following test to OWL Test 
Cases, which illustrates an O(N) construction equivalent to "owl:allDisjoint"

http://www.w3.org/TR/2003/CR-owl-test-20030818/proposedByIssue#I5.21-002

> For the 337 terms in our hypothetical UBL Library ontology, we would
> enter 56616 <owl:disjointWith> statements. Using the proposed
> <owl:allDisjoint> syntax would require 337 statements. 

Recalling the formulae from our group discussion:
http://lists.w3.org/Archives/Public/www-webont-wg/2003Jul/0280

syntax illustrated in test I5.21-002      
6+6*N
2028 triples

owl:disjointWith
N(N+1)/2
56953 triples

"owl:allDisjoint", like owl:AllDistinct
2+4*N
1350 Triples

(In all three, I include the 337 triples needed to declare the classes
xxx rdf:type owl:Class; in the last I include the triples needed for the 
rdf:List construct).

Thus, while owl:allDisjoint is more efficient, it is by a factor of 50%, 
rather than an order of magnitude.

The Working Group does not intend to make any changes in light of your 
comment.

Please reply indicating whether this is a satisfactory response, copying 
public-webont-comments@w3.org

thanks, and please feel free to make more comments,

Jeremy Carroll
]]
Received on Friday, 19 September 2003 08:20:59 GMT

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