- From: Brian McBride <bwm@hplb.hpl.hp.com>
- Date: Thu, 27 Feb 2003 22:25:43 +0000
- To: fmanola@mitre.org, Bob MacGregor <macgregor@isi.edu>
- Cc: www-rdf-comments@w3.org, macgreg@isi.edu
At 16:10 26/02/2003 -0500, Frank Manola wrote: >Brian-- > >Can I have an issue for this please? Basically I'm raising this (or at >least the part about the Primer; You certainly can, but I'm not sure what the issue about the primer is. My (hurried) reading is that Bob is dissatisfied with the specification of reification, not with the primer. I expect that when we discuss an issue, we will consider what other documents are affected by any decision we make and action any appropriate changes. However, if you feel there is a separate issue with the primer, then if you could provide a summary, I'll be happy to record it. Fair? Brian > the message also has a comment about >Concepts) to the WG level because I need input from the WG (especially >Pat, but others may have opinions as well) on how we should handle these >comments about reification. Pat and I need to be in synch on this in >order to also deal with Bob's comments on the Semantics document in >http://lists.w3.org/Archives/Public/www-rdf-comments/2003JanMar/0211.html, >and we also have issue danc-03 raised in >http://lists.w3.org/Archives/Public/www-rdf-comments/2003JanMar/0218.html >that suggests deleting the Primer reification section entirely. And I >recall some messages from Pat about "propositional attitudes" (I can't >recall the thread right now) that are pertinent to Bob's comments. > >--Frank > >Bob MacGregor wrote: > > > > Frank, > > > > At 03:04 PM 2/13/2003 -0500, Frank Manola wrote: > > > > > > >snip > > > > > > > > So, how am I recommending that you fix things? Unfortunately, I'm > mostly > > > > stating what you should NOT do. I'm claiming that > > > > using nested syntax will convey the wrong impression to many > readers (e.g., > > > > those that model belief they way I did above), so something like an > > > > EXPLICIT quotation needs to be included. To me, the use of double > brackets > > > > didn't adequately convey the notion of quotation. > > > > > > >snip > > > > > >I will try using a diagram, rather than what appears to be nested > > >syntax, since we don't support nested syntax (and I didn't intend for > > >what the Primer uses to be interpreted as nested syntax). However, we > > >don't really support explicit quotation either, so we can't really > > >substitute that. Whatever is said in the Primer on reification will > > >have to be consistent with what is said in the Semantics document, which > > >means this is related to your message > > >http://lists.w3.org/Archives/Public/www-rdf-comments/2003JanMar/0211.html > > >"Statings -- Much ado about nothing". > > > > I agree that figuring out a representation is tough. I'm used to KIF, > where > > I can say pretty much anything that I want to. Its hard even to have an > > e-mail conversation about certain aspects of RDF, since the vocabulary just > > isn't available. > > > > > > I consider introducing "what we would *like* to be able to do" very > > > > dangerous. It > > > > gives the impression that RDF might be used to represent propositional > > > > attitudes, > > > > when in fact it can't. I would prefer that the WG be as up front as > > > > possible about > > > > stating the limitations it has placed on RDF. > > > > > >I don't think the Primer actually conveys this impression, and I think > > >it tries to be up front about the limitations of RDF reification (it > > >certainly spends a lot of space talking about them at any rate). > > >However, I could see adding a caveat at the beginning along the lines of > > >"you might think you're going to be able to do foo, but watch carefully, > > >because you can't". Does this make sense? > > > > Yes. Again, we have a vocabulary problem. I've seen the phrase > "propositional > > attitude" pop up now and again, but the notion of "proposition" is quite > > difficult > > to pin down, so that makes it hard to discuss. But, I will try. > > > > I think of propositions as being the proper objects of belief. So, one > doesn't > > believe in a *sentence* "George is a clown". Rather, one believes in the > > proposition > > that that sentence is true. In KIF, I'm used to seeing nested syntax > > employed when > > representing statements about belief. Thus, if RDF allowed nested > > statements, then > > I would use them to represent belief. But it doesn't, and hence I'm > thinking > > that an example that *does* employ nesting gives the wrong impression. > > > > However, the following text appears in the Concepts and > > Abstract Syntax document: > > > > > Not every RDF/XML expression is asserted. Some may convey meaning > > that is partly > > > determined by the circumstances in which they are used. For example, > > in English, a > > > statement "I don't believe that George is a clown" contains the words > > "George is a clown", > > > which, considered in isolation, has the form of an assertion that > > George exhibits certain > > > comic qualities. However, considering the whole sentence, no such > > assertion is considered > > >to be made. > > > > I'm still waiting to see an example of an RDF statement that is not > > asserted. If someone > > could illustrate one, that would be a big help. If, in fact this passage > > is meant to > > refer to reified statements, then please write down how this would look in > > RDF using reified > > statements. > > > > Note: The text above actually uses term "expression" rather than > > "statement" when it > > talks about things being asserted. RDF terms are expressions, and > terms cannot > > be asserted, so that makes the > > first sentence trivially true. But I assume that that was not the authors' > > intent. > > Suggestion: Replace "expression" by "statement" in the first sentence, if > > that's what's > > meant. > > > > My impression is that its impossible to express the sentence > > "I don't believe that George is a clown" > > in RDF. In the OLD RDF, I would have said yes, but not now that we have > > switched > > to "statings". If it is acceptable for a stating to serve as the object of > > a statement > > about belief, then I would have to withdraw my objection. So, can we > represent > > beliefs in RDF? > > > > Cheers, Bob > >-- >Frank Manola The MITRE Corporation >202 Burlington Road, MS A345 Bedford, MA 01730-1420 >mailto:fmanola@mitre.org voice: 781-271-8147 FAX: 781-271-8752
Received on Thursday, 27 February 2003 17:24:41 UTC