LC Responses/JR1

[Draft Response for LC Comment 23] JR1

Dear Jeremy,

Thank you for your message

 http://lists.w3.org/Archives/Public/public-owl-comments/2009Jan/0028.html

on the OWL 2 Web Ontology Language last call drafts.

The WG believes that you are asking for the ability to constrain the kinds of additions that can or, perhaps, should be made to an ontology and/or to constrain certain inferences that can occur over filler classes. The WG realizes that this is indeed a useful ability to have.

This is the province of representation languages that have auto-epistemic features, and native support for this would constitute a major extension to OWL, taking OWL into areas where much less is known about complexity or even decidability of reasoning, where the state of the art in reasoners is much less advanced, and even where there are still disagreements about which language constructs are appropriate. The OWL WG thus has not seriously considered extensions in this direction, instead appropriately waiting for results from research, implementation, and use.

However, there is nothing preventing OWL user interface tools from implementing these extra constraints for additions made through the interface. OWL user interface tools could mark classes as "abstract", meaning that the tool would resist attempts to directly instantiate the class, and could also mark properties in classes as "type required", and check whether the filler belongs to the required class before any addition. OWL user interface tools could even use annotations to record these interface conditions, which would preserve the conditions in the ontology.

The OWL WG has not considered requiring support for these kinds of interface conditions. If there comes to be sufficient use of these kinds of interface conditions, then it may be appropriate for a subsequent working group to consider them.

Therefore, the OWL WG does not intend to make any changes in response to your comment.

Please acknowledge receipt of this email to <mailto:public-owl-comments@w3.org> (replying to this email should suffice). In your acknowledgment please let us know whether or not you are satisfied with the working group's response to your comment.

Regards, Peter F. Patel-Schneider on behalf of the W3C OWL Working Group