- From: Pat Hayes <phayes@ihmc.us>
- Date: Wed, 22 Dec 2004 23:33:48 -0800
- To: Nord File <forhjoklan@yahoo.com>
- Cc: www-rdf-comments@w3.org
>I know the following could seem a little stupid to you, but in my opinion >letting >the "rdfs:range" of "rdfs:predicate" being a not-better-specified >"rdfs:Resource" >just because reifications should be able to model statement errors is pretty >like >letting horses having "things" instead of "feet", just because someone could >erroneously state that a horse has four "frogs" attached to its legs - put >it simple, >it's conceptually incorrect... > >Can you please tell me where exactly is my mistake? Sorry about the long delay in replying. I think your basic mistake is in assuming that RDF is intended to enforce rationality. Part of the point of the semantic web is that information will be published all over the place and from many sources, not all of which can be assumed to be rational or properly formed. That is just asking too much, like requiring that all URIs will always get you a result and 404 errors should be illegal. Part of what makes the Web a success is precisely that it does not set out to be always right, and so it does not fail catastrophically when parts of it go wrong. There are network designs in which (the equivalent of) a 404 error would signal a world-wide disaster, a symptom of some huge breakdown in communication or failure of the network protocol. In the Web REST architecture, it just means some one has given you a bad URI or that some website is down; not a big deal. Similarly for RDF and the semantic web. RDF does not presume that all reified triples are properly managed, since some of them won't be; and so if it were assuming they were, inference failures would propagate. It does not set out to enforce them to be, because that would be inappropriate on an open network; and in any case, there is no way I or anyone else can enforce what you decide to publish. And finally, I would suggest that its not like the horses feet, because there could be genuine disagreements between you and whoever wrote the triples that you are referring to in your reification about what counts as a legal 'rdf:Property'. Presumably if they are not totally confused, they consider those things to be properties: but in YOUR world-view you might disagree. You might have been using them as OWL classes, and OWL-DL does not allow something to be class and a property at the same time. But such a disagreement shouldn't prevent you from QUOTING what they are saying and making some comments about it (such as 'this is crap', maybe) . If RDF insisted as a matter of logic that the things in predicate position had to be properties, then just by referring to them, you would be forced to agree with them. That doesn't seem fair. > >Ok, that's all, I won't bother you anymore, I promise! >Thanks again for your great feedback, > Hope this helps. Happy Holidays. Pat Hayes -- --------------------------------------------------------------------- IHMC (850)434 8903 or (650)494 3973 home 40 South Alcaniz St. (850)202 4416 office Pensacola (850)202 4440 fax FL 32502 (850)291 0667 cell phayes@ihmc.us http://www.ihmc.us/users/phayes
Received on Thursday, 23 December 2004 07:35:59 UTC